2 * Copyright 2015 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 // @author: Andrei Alexandrescu (aalexandre)
20 #ifndef FOLLY_BASE_FBSTRING_H_
21 #define FOLLY_BASE_FBSTRING_H_
25 #include <type_traits>
27 // This file appears in two locations: inside fbcode and in the
28 // libstdc++ source code (when embedding fbstring as std::string).
29 // To aid in this schizophrenic use, _LIBSTDCXX_FBSTRING is defined in
30 // libstdc++'s c++config.h, to gate use inside fbcode v. libstdc++.
31 #ifdef _LIBSTDCXX_FBSTRING
33 #pragma GCC system_header
35 // When used as std::string replacement always disable assertions.
38 #define FOLLY_DEFINED_NDEBUG_FOR_FBSTRING
41 // Handle the cases where the fbcode version (folly/Malloc.h) is included
42 // either before or after this inclusion.
43 #ifdef FOLLY_MALLOC_H_
44 #undef FOLLY_MALLOC_H_
45 #include "basic_fbstring_malloc.h" // nolint
47 #include "basic_fbstring_malloc.h" // nolint
48 #undef FOLLY_MALLOC_H_
51 #else // !_LIBSTDCXX_FBSTRING
53 #include <folly/Portability.h>
55 // libc++ doesn't provide this header, nor does msvc
56 #ifdef FOLLY_HAVE_BITS_CXXCONFIG_H
57 #include <bits/c++config.h>
65 #include <folly/Traits.h>
66 #include <folly/Malloc.h>
67 #include <folly/Hash.h>
68 #include <folly/ScopeGuard.h>
70 #if FOLLY_HAVE_DEPRECATED_ASSOC
71 #ifdef _GLIBCXX_SYMVER
72 #include <ext/hash_set>
73 #include <ext/hash_map>
79 // We defined these here rather than including Likely.h to avoid
80 // redefinition errors when fbstring is imported into libstdc++.
81 #if defined(__GNUC__) && __GNUC__ >= 4
82 #define FBSTRING_LIKELY(x) (__builtin_expect((x), 1))
83 #define FBSTRING_UNLIKELY(x) (__builtin_expect((x), 0))
85 #define FBSTRING_LIKELY(x) (x)
86 #define FBSTRING_UNLIKELY(x) (x)
89 // Ignore shadowing warnings within this file, so includers can use -Wshadow.
90 #pragma GCC diagnostic push
91 #pragma GCC diagnostic ignored "-Wshadow"
93 // FBString cannot use throw when replacing std::string, though it may still
96 #define throw FOLLY_FBSTRING_MAY_NOT_USE_THROW
98 #ifdef _LIBSTDCXX_FBSTRING
99 namespace std _GLIBCXX_VISIBILITY(default) {
100 _GLIBCXX_BEGIN_NAMESPACE_VERSION
105 // Different versions of gcc/clang support different versions of
106 // the address sanitizer attribute. Unfortunately, this attribute
107 // has issues when inlining is used, so disable that as well.
108 #if defined(__clang__)
109 # if __has_feature(address_sanitizer)
110 # if __has_attribute(__no_sanitize__)
111 # define FBSTRING_DISABLE_ADDRESS_SANITIZER \
112 __attribute__((__no_sanitize__("address"), __noinline__))
113 # elif __has_attribute(__no_address_safety_analysis__)
114 # define FBSTRING_DISABLE_ADDRESS_SANITIZER \
115 __attribute__((__no_address_safety_analysis__, __noinline__))
116 # elif __has_attribute(__no_sanitize_address__)
117 # define FBSTRING_DISABLE_ADDRESS_SANITIZER \
118 __attribute__((__no_sanitize_address__, __noinline__))
121 #elif defined (__GNUC__) && \
123 # define FBSTRING_DISABLE_ADDRESS_SANITIZER \
124 __attribute__((__no_address_safety_analysis__, __noinline__))
126 #ifndef FBSTRING_DISABLE_ADDRESS_SANITIZER
127 # define FBSTRING_DISABLE_ADDRESS_SANITIZER
130 namespace fbstring_detail {
132 template <class InIt, class OutIt>
135 typename std::iterator_traits<InIt>::difference_type n,
137 for (; n != 0; --n, ++b, ++d) {
143 template <class Pod, class T>
144 inline void pod_fill(Pod* b, Pod* e, T c) {
145 assert(b && e && b <= e);
146 /*static*/ if (sizeof(T) == 1) {
149 auto const ee = b + ((e - b) & ~7u);
150 for (; b != ee; b += 8) {
161 for (; b != e; ++b) {
168 * Lightly structured memcpy, simplifies copying PODs and introduces
169 * some asserts. Unfortunately using this function may cause
170 * measurable overhead (presumably because it adjusts from a begin/end
171 * convention to a pointer/size convention, so it does some extra
172 * arithmetic even though the caller might have done the inverse
173 * adaptation outside).
176 inline void pod_copy(const Pod* b, const Pod* e, Pod* d) {
178 assert(d >= e || d + (e - b) <= b);
179 memcpy(d, b, (e - b) * sizeof(Pod));
183 * Lightly structured memmove, simplifies copying PODs and introduces
187 inline void pod_move(const Pod* b, const Pod* e, Pod* d) {
189 memmove(d, b, (e - b) * sizeof(*b));
192 } // namespace fbstring_detail
195 * Defines a special acquisition method for constructing fbstring
196 * objects. AcquireMallocatedString means that the user passes a
197 * pointer to a malloc-allocated string that the fbstring object will
200 enum class AcquireMallocatedString {};
203 * fbstring_core_model is a mock-up type that defines all required
204 * signatures of a fbstring core. The fbstring class itself uses such
205 * a core object to implement all of the numerous member functions
206 * required by the standard.
208 * If you want to define a new core, copy the definition below and
209 * implement the primitives. Then plug the core into basic_fbstring as
210 * a template argument.
212 template <class Char>
213 class fbstring_core_model {
215 fbstring_core_model();
216 fbstring_core_model(const fbstring_core_model &);
217 ~fbstring_core_model();
218 // Returns a pointer to string's buffer (currently only contiguous
219 // strings are supported). The pointer is guaranteed to be valid
220 // until the next call to a non-const member function.
221 const Char * data() const;
222 // Much like data(), except the string is prepared to support
223 // character-level changes. This call is a signal for
224 // e.g. reference-counted implementation to fork the data. The
225 // pointer is guaranteed to be valid until the next call to a
226 // non-const member function.
227 Char * mutable_data();
228 // Returns a pointer to string's buffer and guarantees that a
229 // readable '\0' lies right after the buffer. The pointer is
230 // guaranteed to be valid until the next call to a non-const member
232 const Char * c_str() const;
233 // Shrinks the string by delta characters. Asserts that delta <=
235 void shrink(size_t delta);
236 // Expands the string by delta characters (i.e. after this call
237 // size() will report the old size() plus delta) but without
238 // initializing the expanded region. Returns a pointer to the memory
239 // to be initialized (the beginning of the expanded portion). The
240 // caller is expected to fill the expanded area appropriately.
241 Char* expand_noinit(size_t delta);
242 // Expands the string by one character and sets the last character
244 void push_back(Char c);
245 // Returns the string's size.
247 // Returns the string's capacity, i.e. maximum size that the string
248 // can grow to without reallocation. Note that for reference counted
249 // strings that's technically a lie - even assigning characters
250 // within the existing size would cause a reallocation.
251 size_t capacity() const;
252 // Returns true if the data underlying the string is actually shared
253 // across multiple strings (in a refcounted fashion).
254 bool isShared() const;
255 // Makes sure that at least minCapacity characters are available for
256 // the string without reallocation. For reference-counted strings,
257 // it should fork the data even if minCapacity < size().
258 void reserve(size_t minCapacity);
261 fbstring_core_model& operator=(const fbstring_core_model &);
266 * This is the core of the string. The code should work on 32- and
267 * 64-bit and both big- and little-endianan architectures with any
270 * The storage is selected as follows (assuming we store one-byte
271 * characters on a 64-bit machine): (a) "small" strings between 0 and
272 * 23 chars are stored in-situ without allocation (the rightmost byte
273 * stores the size); (b) "medium" strings from 24 through 254 chars
274 * are stored in malloc-allocated memory that is copied eagerly; (c)
275 * "large" strings of 255 chars and above are stored in a similar
276 * structure as medium arrays, except that the string is
277 * reference-counted and copied lazily. the reference count is
278 * allocated right before the character array.
280 * The discriminator between these three strategies sits in two
281 * bits of the rightmost char of the storage. If neither is set, then the
282 * string is small (and its length sits in the lower-order bits on
283 * little-endian or the high-order bits on big-endian of that
284 * rightmost character). If the MSb is set, the string is medium width.
285 * If the second MSb is set, then the string is large. On little-endian,
286 * these 2 bits are the 2 MSbs of MediumLarge::capacity_, while on
287 * big-endian, these 2 bits are the 2 LSbs. This keeps both little-endian
288 * and big-endian fbstring_core equivalent with merely different ops used
289 * to extract capacity/category.
291 template <class Char> class fbstring_core {
293 fbstring_core() noexcept { reset(); }
295 fbstring_core(const fbstring_core & rhs) {
296 assert(&rhs != this);
297 // Simplest case first: small strings are bitblitted
298 if (rhs.category() == Category::isSmall) {
299 static_assert(offsetof(MediumLarge, data_) == 0,
300 "fbstring layout failure");
301 static_assert(offsetof(MediumLarge, size_) == sizeof(ml_.data_),
302 "fbstring layout failure");
303 static_assert(offsetof(MediumLarge, capacity_) == 2 * sizeof(ml_.data_),
304 "fbstring layout failure");
305 // Just write the whole thing, don't look at details. In
306 // particular we need to copy capacity anyway because we want
307 // to set the size (don't forget that the last character,
308 // which stores a short string's length, is shared with the
309 // ml_.capacity field).
311 assert(category() == Category::isSmall && this->size() == rhs.size());
312 } else if (rhs.category() == Category::isLarge) {
313 // Large strings are just refcounted
315 RefCounted::incrementRefs(ml_.data_);
316 assert(category() == Category::isLarge && size() == rhs.size());
318 // Medium strings are copied eagerly. Don't forget to allocate
319 // one extra Char for the null terminator.
320 auto const allocSize =
321 goodMallocSize((1 + rhs.ml_.size_) * sizeof(Char));
322 ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
323 fbstring_detail::pod_copy(rhs.ml_.data_,
325 rhs.ml_.data_ + rhs.ml_.size_ + 1,
327 // No need for writeTerminator() here, we copied one extra
328 // element just above.
329 ml_.size_ = rhs.ml_.size_;
330 ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
331 assert(category() == Category::isMedium);
333 assert(size() == rhs.size());
334 assert(memcmp(data(), rhs.data(), size() * sizeof(Char)) == 0);
337 fbstring_core(fbstring_core&& goner) noexcept {
340 if (goner.category() != Category::isSmall) {
341 // Clean goner's carcass
346 // NOTE(agallagher): The word-aligned copy path copies bytes which are
347 // outside the range of the string, and makes address sanitizer unhappy,
348 // so just disable it on this function.
349 fbstring_core(const Char *const data, const size_t size)
350 FBSTRING_DISABLE_ADDRESS_SANITIZER {
352 #ifndef _LIBSTDCXX_FBSTRING
354 assert(this->size() == size);
355 assert(memcmp(this->data(), data, size * sizeof(Char)) == 0);
360 // Simplest case first: small strings are bitblitted
361 if (size <= maxSmallSize) {
362 // Layout is: Char* data_, size_t size_, size_t capacity_
363 static_assert(sizeof(*this) == sizeof(Char*) + 2 * sizeof(size_t),
364 "fbstring has unexpected size");
365 static_assert(sizeof(Char*) == sizeof(size_t),
366 "fbstring size assumption violation");
367 // sizeof(size_t) must be a power of 2
368 static_assert((sizeof(size_t) & (sizeof(size_t) - 1)) == 0,
369 "fbstring size assumption violation");
371 // If data is aligned, use fast word-wise copying. Otherwise,
372 // use conservative memcpy.
373 if (reinterpret_cast<size_t>(data) & (sizeof(size_t) - 1)) {
374 fbstring_detail::pod_copy(data, data + size, small_);
376 // Copy one word (64 bits) at a time
377 const size_t byteSize = size * sizeof(Char);
378 if (byteSize > 2 * sizeof(size_t)) {
380 ml_.capacity_ = reinterpret_cast<const size_t*>(data)[2];
382 ml_.size_ = reinterpret_cast<const size_t*>(data)[1];
384 ml_.data_ = *reinterpret_cast<Char**>(const_cast<Char*>(data));
385 } else if (byteSize > sizeof(size_t)) {
388 } else if (size > 0) {
395 } else if (size <= maxMediumSize) {
396 // Medium strings are allocated normally. Don't forget to
397 // allocate one extra Char for the terminating null.
398 auto const allocSize = goodMallocSize((1 + size) * sizeof(Char));
399 ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
400 fbstring_detail::pod_copy(data, data + size, ml_.data_);
402 ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
404 // Large strings are allocated differently
405 size_t effectiveCapacity = size;
406 auto const newRC = RefCounted::create(data, & effectiveCapacity);
407 ml_.data_ = newRC->data_;
409 ml_.setCapacity(effectiveCapacity, Category::isLarge);
414 ~fbstring_core() noexcept {
415 auto const c = category();
416 if (c == Category::isSmall) {
419 if (c == Category::isMedium) {
423 RefCounted::decrementRefs(ml_.data_);
426 // Snatches a previously mallocated string. The parameter "size"
427 // is the size of the string, and the parameter "allocatedSize"
428 // is the size of the mallocated block. The string must be
429 // \0-terminated, so allocatedSize >= size + 1 and data[size] == '\0'.
431 // So if you want a 2-character string, pass malloc(3) as "data",
432 // pass 2 as "size", and pass 3 as "allocatedSize".
433 fbstring_core(Char * const data,
435 const size_t allocatedSize,
436 AcquireMallocatedString) {
438 assert(allocatedSize >= size + 1);
439 assert(data[size] == '\0');
440 // Use the medium string storage
443 // Don't forget about null terminator
444 ml_.setCapacity(allocatedSize - 1, Category::isMedium);
446 // No need for the memory
452 // swap below doesn't test whether &rhs == this (and instead
453 // potentially does extra work) on the premise that the rarity of
454 // that situation actually makes the check more expensive than is
456 void swap(fbstring_core & rhs) {
462 // In C++11 data() and c_str() are 100% equivalent.
463 const Char * data() const {
467 Char * mutable_data() {
468 auto const c = category();
469 if (c == Category::isSmall) {
472 assert(c == Category::isMedium || c == Category::isLarge);
473 if (c == Category::isLarge && RefCounted::refs(ml_.data_) > 1) {
475 size_t effectiveCapacity = ml_.capacity();
476 auto const newRC = RefCounted::create(& effectiveCapacity);
477 // If this fails, someone placed the wrong capacity in an
479 assert(effectiveCapacity >= ml_.capacity());
480 fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_ + 1,
482 RefCounted::decrementRefs(ml_.data_);
483 ml_.data_ = newRC->data_;
484 // No need to call writeTerminator(), we have + 1 above.
489 const Char * c_str() const {
490 auto const c = category();
491 if (c == Category::isSmall) {
492 assert(small_[smallSize()] == '\0');
495 assert(c == Category::isMedium || c == Category::isLarge);
496 assert(ml_.data_[ml_.size_] == '\0');
500 void shrink(const size_t delta) {
501 if (category() == Category::isSmall) {
502 // Check for underflow
503 assert(delta <= smallSize());
504 setSmallSize(smallSize() - delta);
505 } else if (category() == Category::isMedium ||
506 RefCounted::refs(ml_.data_) == 1) {
507 // Medium strings and unique large strings need no special
509 assert(ml_.size_ >= delta);
513 assert(ml_.size_ >= delta);
514 // Shared large string, must make unique. This is because of the
515 // durn terminator must be written, which may trample the shared
518 fbstring_core(ml_.data_, ml_.size_ - delta).swap(*this);
520 // No need to write the terminator.
524 void reserve(size_t minCapacity) {
525 if (category() == Category::isLarge) {
527 if (RefCounted::refs(ml_.data_) > 1) {
528 // We must make it unique regardless; in-place reallocation is
529 // useless if the string is shared. In order to not surprise
530 // people, reserve the new block at current capacity or
531 // more. That way, a string's capacity never shrinks after a
533 minCapacity = std::max(minCapacity, ml_.capacity());
534 auto const newRC = RefCounted::create(& minCapacity);
535 fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_ + 1,
537 // Done with the old data. No need to call writeTerminator(),
538 // we have + 1 above.
539 RefCounted::decrementRefs(ml_.data_);
540 ml_.data_ = newRC->data_;
541 ml_.setCapacity(minCapacity, Category::isLarge);
542 // size remains unchanged
544 // String is not shared, so let's try to realloc (if needed)
545 if (minCapacity > ml_.capacity()) {
546 // Asking for more memory
548 RefCounted::reallocate(ml_.data_, ml_.size_,
549 ml_.capacity(), minCapacity);
550 ml_.data_ = newRC->data_;
551 ml_.setCapacity(minCapacity, Category::isLarge);
554 assert(capacity() >= minCapacity);
556 } else if (category() == Category::isMedium) {
557 // String is not shared
558 if (minCapacity <= ml_.capacity()) {
559 return; // nothing to do, there's enough room
561 if (minCapacity <= maxMediumSize) {
562 // Keep the string at medium size. Don't forget to allocate
563 // one extra Char for the terminating null.
564 size_t capacityBytes = goodMallocSize((1 + minCapacity) * sizeof(Char));
565 ml_.data_ = static_cast<Char *>(
568 ml_.size_ * sizeof(Char),
569 (ml_.capacity() + 1) * sizeof(Char),
572 ml_.setCapacity(capacityBytes / sizeof(Char) - 1, Category::isMedium);
574 // Conversion from medium to large string
575 fbstring_core nascent;
576 // Will recurse to another branch of this function
577 nascent.reserve(minCapacity);
578 nascent.ml_.size_ = ml_.size_;
579 fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_,
583 assert(capacity() >= minCapacity);
586 assert(category() == Category::isSmall);
587 if (minCapacity > maxMediumSize) {
589 auto const newRC = RefCounted::create(& minCapacity);
590 auto const size = smallSize();
591 fbstring_detail::pod_copy(small_, small_ + size + 1, newRC->data_);
592 // No need for writeTerminator(), we wrote it above with + 1.
593 ml_.data_ = newRC->data_;
595 ml_.setCapacity(minCapacity, Category::isLarge);
596 assert(capacity() >= minCapacity);
597 } else if (minCapacity > maxSmallSize) {
599 // Don't forget to allocate one extra Char for the terminating null
600 auto const allocSizeBytes =
601 goodMallocSize((1 + minCapacity) * sizeof(Char));
602 auto const data = static_cast<Char*>(checkedMalloc(allocSizeBytes));
603 auto const size = smallSize();
604 fbstring_detail::pod_copy(small_, small_ + size + 1, data);
605 // No need for writeTerminator(), we wrote it above with + 1.
608 ml_.setCapacity(allocSizeBytes / sizeof(Char) - 1, Category::isMedium);
611 // Nothing to do, everything stays put
614 assert(capacity() >= minCapacity);
617 Char * expand_noinit(const size_t delta) {
618 // Strategy is simple: make room, then change size
619 assert(capacity() >= size());
621 if (category() == Category::isSmall) {
624 if (newSz <= maxSmallSize) {
631 newSz = ml_.size_ + delta;
632 if (newSz > capacity()) {
636 assert(capacity() >= newSz);
637 // Category can't be small - we took care of that above
638 assert(category() == Category::isMedium || category() == Category::isLarge);
641 assert(size() == newSz);
642 return ml_.data_ + sz;
645 void push_back(Char c) {
646 assert(capacity() >= size());
648 if (category() == Category::isSmall) {
650 if (sz < maxSmallSize) {
652 setSmallSize(sz + 1);
655 reserve(maxSmallSize * 2);
658 if (sz == capacity()) { // always true for isShared()
659 reserve(1 + sz * 3 / 2); // ensures not shared
663 assert(capacity() >= sz + 1);
664 // Category can't be small - we took care of that above
665 assert(category() == Category::isMedium || category() == Category::isLarge);
671 size_t size() const {
672 return category() == Category::isSmall ? smallSize() : ml_.size_;
675 size_t capacity() const {
676 switch (category()) {
677 case Category::isSmall:
679 case Category::isLarge:
680 // For large-sized strings, a multi-referenced chunk has no
681 // available capacity. This is because any attempt to append
682 // data would trigger a new allocation.
683 if (RefCounted::refs(ml_.data_) > 1) return ml_.size_;
686 return ml_.capacity();
689 bool isShared() const {
690 return category() == Category::isLarge && RefCounted::refs(ml_.data_) > 1;
693 void writeTerminator() {
694 if (category() == Category::isSmall) {
695 const auto s = smallSize();
696 if (s != maxSmallSize) {
700 ml_.data_[ml_.size_] = '\0';
706 fbstring_core & operator=(const fbstring_core & rhs);
708 // Equivalent to setSmallSize(0), but with specialized
709 // writeTerminator which doesn't re-check the category after
710 // capacity_ is overwritten.
712 // Only initialize the tag, will set the MSBs (i.e. the small
713 // string size) to zero too.
714 ml_.capacity_ = kIsLittleEndian
715 ? maxSmallSize << (8 * (sizeof(size_t) - sizeof(Char)))
718 assert(category() == Category::isSmall && size() == 0);
722 std::atomic<size_t> refCount_;
725 static RefCounted * fromData(Char * p) {
726 return static_cast<RefCounted*>(
728 static_cast<unsigned char*>(static_cast<void*>(p))
729 - sizeof(refCount_)));
732 static size_t refs(Char * p) {
733 return fromData(p)->refCount_.load(std::memory_order_acquire);
736 static void incrementRefs(Char * p) {
737 fromData(p)->refCount_.fetch_add(1, std::memory_order_acq_rel);
740 static void decrementRefs(Char * p) {
741 auto const dis = fromData(p);
742 size_t oldcnt = dis->refCount_.fetch_sub(1, std::memory_order_acq_rel);
749 static RefCounted * create(size_t * size) {
750 // Don't forget to allocate one extra Char for the terminating
751 // null. In this case, however, one Char is already part of the
753 const size_t allocSize = goodMallocSize(
754 sizeof(RefCounted) + *size * sizeof(Char));
755 auto result = static_cast<RefCounted*>(checkedMalloc(allocSize));
756 result->refCount_.store(1, std::memory_order_release);
757 *size = (allocSize - sizeof(RefCounted)) / sizeof(Char);
761 static RefCounted * create(const Char * data, size_t * size) {
762 const size_t effectiveSize = *size;
763 auto result = create(size);
764 fbstring_detail::pod_copy(data, data + effectiveSize, result->data_);
768 static RefCounted * reallocate(Char *const data,
769 const size_t currentSize,
770 const size_t currentCapacity,
771 const size_t newCapacity) {
772 assert(newCapacity > 0 && newCapacity > currentSize);
773 auto const dis = fromData(data);
774 assert(dis->refCount_.load(std::memory_order_acquire) == 1);
775 // Don't forget to allocate one extra Char for the terminating
776 // null. In this case, however, one Char is already part of the
778 auto result = static_cast<RefCounted*>(
780 sizeof(RefCounted) + currentSize * sizeof(Char),
781 sizeof(RefCounted) + currentCapacity * sizeof(Char),
782 sizeof(RefCounted) + newCapacity * sizeof(Char)));
783 assert(result->refCount_.load(std::memory_order_acquire) == 1);
788 typedef std::conditional<sizeof(size_t) == 4, uint32_t, uint64_t>::type
791 enum class Category : category_type {
793 isMedium = kIsLittleEndian
794 ? sizeof(size_t) == 4 ? 0x80000000 : 0x8000000000000000
796 isLarge = kIsLittleEndian
797 ? sizeof(size_t) == 4 ? 0x40000000 : 0x4000000000000000
801 Category category() const {
802 // works for both big-endian and little-endian
803 return static_cast<Category>(ml_.capacity_ & categoryExtractMask);
811 size_t capacity() const {
812 return kIsLittleEndian
813 ? capacity_ & capacityExtractMask
817 void setCapacity(size_t cap, Category cat) {
818 capacity_ = kIsLittleEndian
819 ? cap | static_cast<category_type>(cat)
820 : (cap << 2) | static_cast<category_type>(cat);
825 Char small_[sizeof(MediumLarge) / sizeof(Char)];
830 lastChar = sizeof(MediumLarge) - 1,
831 maxSmallSize = lastChar / sizeof(Char),
832 maxMediumSize = 254 / sizeof(Char), // coincides with the small
833 // bin size in dlmalloc
834 categoryExtractMask = kIsLittleEndian
835 ? sizeof(size_t) == 4 ? 0xC0000000 : 0xC000000000000000
837 capacityExtractMask = kIsLittleEndian
838 ? ~categoryExtractMask
841 static_assert(!(sizeof(MediumLarge) % sizeof(Char)),
842 "Corrupt memory layout for fbstring.");
844 size_t smallSize() const {
845 assert(category() == Category::isSmall);
846 auto shift = kIsLittleEndian ? 0 : 2;
847 auto smallShifted = static_cast<size_t>(small_[maxSmallSize]) >> shift;
848 assert(static_cast<size_t>(maxSmallSize) >= smallShifted);
849 return static_cast<size_t>(maxSmallSize) - smallShifted;
852 void setSmallSize(size_t s) {
853 // Warning: this should work with uninitialized strings too,
854 // so don't assume anything about the previous value of
855 // small_[maxSmallSize].
856 assert(s <= maxSmallSize);
857 small_[maxSmallSize] = kIsLittleEndian
859 : (maxSmallSize - s) << 2;
864 #ifndef _LIBSTDCXX_FBSTRING
866 * Dummy fbstring core that uses an actual std::string. This doesn't
867 * make any sense - it's just for testing purposes.
869 template <class Char>
870 class dummy_fbstring_core {
872 dummy_fbstring_core() {
874 dummy_fbstring_core(const dummy_fbstring_core& another)
875 : backend_(another.backend_) {
877 dummy_fbstring_core(const Char * s, size_t n)
880 void swap(dummy_fbstring_core & rhs) {
881 backend_.swap(rhs.backend_);
883 const Char * data() const {
884 return backend_.data();
886 Char * mutable_data() {
887 //assert(!backend_.empty());
888 return &*backend_.begin();
890 void shrink(size_t delta) {
891 assert(delta <= size());
892 backend_.resize(size() - delta);
894 Char * expand_noinit(size_t delta) {
895 auto const sz = size();
896 backend_.resize(size() + delta);
897 return backend_.data() + sz;
899 void push_back(Char c) {
900 backend_.push_back(c);
902 size_t size() const {
903 return backend_.size();
905 size_t capacity() const {
906 return backend_.capacity();
908 bool isShared() const {
911 void reserve(size_t minCapacity) {
912 backend_.reserve(minCapacity);
916 std::basic_string<Char> backend_;
918 #endif // !_LIBSTDCXX_FBSTRING
921 * This is the basic_string replacement. For conformity,
922 * basic_fbstring takes the same template parameters, plus the last
923 * one which is the core.
925 #ifdef _LIBSTDCXX_FBSTRING
926 template <typename E, class T, class A, class Storage>
928 template <typename E,
929 class T = std::char_traits<E>,
930 class A = std::allocator<E>,
931 class Storage = fbstring_core<E> >
933 class basic_fbstring {
937 void (*throw_exc)(const char*),
939 if (!condition) throw_exc(msg);
942 bool isSane() const {
945 empty() == (size() == 0) &&
946 empty() == (begin() == end()) &&
947 size() <= max_size() &&
948 capacity() <= max_size() &&
949 size() <= capacity() &&
950 begin()[size()] == '\0';
954 friend struct Invariant;
957 explicit Invariant(const basic_fbstring& s) : s_(s) {
964 const basic_fbstring& s_;
966 explicit Invariant(const basic_fbstring&) {}
968 Invariant& operator=(const Invariant&);
973 typedef T traits_type;
974 typedef typename traits_type::char_type value_type;
975 typedef A allocator_type;
976 typedef typename A::size_type size_type;
977 typedef typename A::difference_type difference_type;
979 typedef typename A::reference reference;
980 typedef typename A::const_reference const_reference;
981 typedef typename A::pointer pointer;
982 typedef typename A::const_pointer const_pointer;
985 typedef const E* const_iterator;
986 typedef std::reverse_iterator<iterator
987 #ifdef NO_ITERATOR_TRAITS
991 typedef std::reverse_iterator<const_iterator
992 #ifdef NO_ITERATOR_TRAITS
995 > const_reverse_iterator;
997 static const size_type npos; // = size_type(-1)
1000 static void procrustes(size_type& n, size_type nmax) {
1001 if (n > nmax) n = nmax;
1005 // C++11 21.4.2 construct/copy/destroy
1007 // Note: while the following two constructors can be (and previously were)
1008 // collapsed into one constructor written this way:
1010 // explicit basic_fbstring(const A& a = A()) noexcept { }
1012 // This can cause Clang (at least version 3.7) to fail with the error:
1013 // "chosen constructor is explicit in copy-initialization ...
1014 // in implicit initialization of field '(x)' with omitted initializer"
1016 // if used in a struct which is default-initialized. Hence the split into
1017 // these two separate constructors.
1019 basic_fbstring() noexcept : basic_fbstring(A()) {
1022 explicit basic_fbstring(const A&) noexcept {
1025 basic_fbstring(const basic_fbstring& str)
1026 : store_(str.store_) {
1030 basic_fbstring(basic_fbstring&& goner) noexcept
1031 : store_(std::move(goner.store_)) {
1034 #ifndef _LIBSTDCXX_FBSTRING
1035 // This is defined for compatibility with std::string
1036 /* implicit */ basic_fbstring(const std::string& str)
1037 : store_(str.data(), str.size()) {
1041 basic_fbstring(const basic_fbstring& str,
1044 const A& /* a */ = A()) {
1045 assign(str, pos, n);
1048 /* implicit */ basic_fbstring(const value_type* s, const A& /*a*/ = A())
1050 ? traits_type::length(s)
1051 : (std::__throw_logic_error(
1052 "basic_fbstring: null pointer initializer not valid"),
1056 basic_fbstring(const value_type* s, size_type n, const A& /*a*/ = A())
1060 basic_fbstring(size_type n, value_type c, const A& /*a*/ = A()) {
1061 auto const data = store_.expand_noinit(n);
1062 fbstring_detail::pod_fill(data, data + n, c);
1063 store_.writeTerminator();
1066 template <class InIt>
1067 basic_fbstring(InIt begin, InIt end,
1068 typename std::enable_if<
1069 !std::is_same<typename std::remove_const<InIt>::type,
1070 value_type*>::value, const A>::type & /*a*/ = A()) {
1074 // Specialization for const char*, const char*
1075 basic_fbstring(const value_type* b, const value_type* e)
1076 : store_(b, e - b) {
1079 // Nonstandard constructor
1080 basic_fbstring(value_type *s, size_type n, size_type c,
1081 AcquireMallocatedString a)
1082 : store_(s, n, c, a) {
1085 // Construction from initialization list
1086 basic_fbstring(std::initializer_list<value_type> il) {
1087 assign(il.begin(), il.end());
1090 ~basic_fbstring() noexcept {
1093 basic_fbstring& operator=(const basic_fbstring& lhs) {
1094 if (FBSTRING_UNLIKELY(&lhs == this)) {
1097 auto const oldSize = size();
1098 auto const srcSize = lhs.size();
1099 if (capacity() >= srcSize && !store_.isShared()) {
1100 // great, just copy the contents
1101 if (oldSize < srcSize)
1102 store_.expand_noinit(srcSize - oldSize);
1104 store_.shrink(oldSize - srcSize);
1105 assert(size() == srcSize);
1106 fbstring_detail::pod_copy(lhs.begin(), lhs.end(), begin());
1107 store_.writeTerminator();
1109 // need to reallocate, so we may as well create a brand new string
1110 basic_fbstring(lhs).swap(*this);
1116 basic_fbstring& operator=(basic_fbstring&& goner) noexcept {
1117 if (FBSTRING_UNLIKELY(&goner == this)) {
1118 // Compatibility with std::basic_string<>,
1119 // C++11 21.4.2 [string.cons] / 23 requires self-move-assignment support.
1122 // No need of this anymore
1123 this->~basic_fbstring();
1124 // Move the goner into this
1125 new(&store_) fbstring_core<E>(std::move(goner.store_));
1129 #ifndef _LIBSTDCXX_FBSTRING
1130 // Compatibility with std::string
1131 basic_fbstring & operator=(const std::string & rhs) {
1132 return assign(rhs.data(), rhs.size());
1135 // Compatibility with std::string
1136 std::string toStdString() const {
1137 return std::string(data(), size());
1140 // A lot of code in fbcode still uses this method, so keep it here for now.
1141 const basic_fbstring& toStdString() const {
1146 basic_fbstring& operator=(const value_type* s) {
1150 basic_fbstring& operator=(value_type c) {
1152 store_.expand_noinit(1);
1153 } else if (store_.isShared()) {
1154 basic_fbstring(1, c).swap(*this);
1157 store_.shrink(size() - 1);
1159 *store_.mutable_data() = c;
1160 store_.writeTerminator();
1164 basic_fbstring& operator=(std::initializer_list<value_type> il) {
1165 return assign(il.begin(), il.end());
1168 // C++11 21.4.3 iterators:
1169 iterator begin() { return store_.mutable_data(); }
1171 const_iterator begin() const { return store_.data(); }
1173 const_iterator cbegin() const { return begin(); }
1176 return store_.mutable_data() + store_.size();
1179 const_iterator end() const {
1180 return store_.data() + store_.size();
1183 const_iterator cend() const { return end(); }
1185 reverse_iterator rbegin() {
1186 return reverse_iterator(end());
1189 const_reverse_iterator rbegin() const {
1190 return const_reverse_iterator(end());
1193 const_reverse_iterator crbegin() const { return rbegin(); }
1195 reverse_iterator rend() {
1196 return reverse_iterator(begin());
1199 const_reverse_iterator rend() const {
1200 return const_reverse_iterator(begin());
1203 const_reverse_iterator crend() const { return rend(); }
1206 // C++11 21.4.5, element access:
1207 const value_type& front() const { return *begin(); }
1208 const value_type& back() const {
1210 // Should be begin()[size() - 1], but that branches twice
1211 return *(end() - 1);
1213 value_type& front() { return *begin(); }
1214 value_type& back() {
1216 // Should be begin()[size() - 1], but that branches twice
1217 return *(end() - 1);
1224 // C++11 21.4.4 capacity:
1225 size_type size() const { return store_.size(); }
1227 size_type length() const { return size(); }
1229 size_type max_size() const {
1230 return std::numeric_limits<size_type>::max();
1233 void resize(const size_type n, const value_type c = value_type()) {
1234 auto size = this->size();
1236 store_.shrink(size - n);
1238 // Do this in two steps to minimize slack memory copied (see
1240 auto const capacity = this->capacity();
1241 assert(capacity >= size);
1242 if (size < capacity) {
1243 auto delta = std::min(n, capacity) - size;
1244 store_.expand_noinit(delta);
1245 fbstring_detail::pod_fill(begin() + size, end(), c);
1248 store_.writeTerminator();
1253 auto const delta = n - size;
1254 store_.expand_noinit(delta);
1255 fbstring_detail::pod_fill(end() - delta, end(), c);
1256 store_.writeTerminator();
1258 assert(this->size() == n);
1261 size_type capacity() const { return store_.capacity(); }
1263 void reserve(size_type res_arg = 0) {
1264 enforce(res_arg <= max_size(), std::__throw_length_error, "");
1265 store_.reserve(res_arg);
1268 void shrink_to_fit() {
1269 // Shrink only if slack memory is sufficiently large
1270 if (capacity() < size() * 3 / 2) {
1273 basic_fbstring(cbegin(), cend()).swap(*this);
1276 void clear() { resize(0); }
1278 bool empty() const { return size() == 0; }
1280 // C++11 21.4.5 element access:
1281 const_reference operator[](size_type pos) const {
1282 return *(begin() + pos);
1285 reference operator[](size_type pos) {
1286 return *(begin() + pos);
1289 const_reference at(size_type n) const {
1290 enforce(n <= size(), std::__throw_out_of_range, "");
1294 reference at(size_type n) {
1295 enforce(n < size(), std::__throw_out_of_range, "");
1299 // C++11 21.4.6 modifiers:
1300 basic_fbstring& operator+=(const basic_fbstring& str) {
1304 basic_fbstring& operator+=(const value_type* s) {
1308 basic_fbstring& operator+=(const value_type c) {
1313 basic_fbstring& operator+=(std::initializer_list<value_type> il) {
1318 basic_fbstring& append(const basic_fbstring& str) {
1320 auto desiredSize = size() + str.size();
1322 append(str.data(), str.size());
1323 assert(size() == desiredSize);
1327 basic_fbstring& append(const basic_fbstring& str, const size_type pos,
1329 const size_type sz = str.size();
1330 enforce(pos <= sz, std::__throw_out_of_range, "");
1331 procrustes(n, sz - pos);
1332 return append(str.data() + pos, n);
1335 basic_fbstring& append(const value_type* s, size_type n) {
1337 Invariant checker(*this);
1340 if (FBSTRING_UNLIKELY(!n)) {
1341 // Unlikely but must be done
1344 auto const oldSize = size();
1345 auto const oldData = data();
1346 // Check for aliasing (rare). We could use "<=" here but in theory
1347 // those do not work for pointers unless the pointers point to
1348 // elements in the same array. For that reason we use
1349 // std::less_equal, which is guaranteed to offer a total order
1350 // over pointers. See discussion at http://goo.gl/Cy2ya for more
1352 std::less_equal<const value_type*> le;
1353 if (FBSTRING_UNLIKELY(le(oldData, s) && !le(oldData + oldSize, s))) {
1354 assert(le(s + n, oldData + oldSize));
1355 const size_type offset = s - oldData;
1356 store_.reserve(oldSize + n);
1357 // Restore the source
1358 s = data() + offset;
1360 // Warning! Repeated appends with short strings may actually incur
1361 // practically quadratic performance. Avoid that by pushing back
1362 // the first character (which ensures exponential growth) and then
1363 // appending the rest normally. Worst case the append may incur a
1364 // second allocation but that will be rare.
1367 memcpy(store_.expand_noinit(n), s, n * sizeof(value_type));
1368 assert(size() == oldSize + n + 1);
1372 basic_fbstring& append(const value_type* s) {
1373 return append(s, traits_type::length(s));
1376 basic_fbstring& append(size_type n, value_type c) {
1377 resize(size() + n, c);
1381 template<class InputIterator>
1382 basic_fbstring& append(InputIterator first, InputIterator last) {
1383 insert(end(), first, last);
1387 basic_fbstring& append(std::initializer_list<value_type> il) {
1388 return append(il.begin(), il.end());
1391 void push_back(const value_type c) { // primitive
1392 store_.push_back(c);
1395 basic_fbstring& assign(const basic_fbstring& str) {
1396 if (&str == this) return *this;
1397 return assign(str.data(), str.size());
1400 basic_fbstring& assign(basic_fbstring&& str) {
1401 return *this = std::move(str);
1404 basic_fbstring& assign(const basic_fbstring& str, const size_type pos,
1406 const size_type sz = str.size();
1407 enforce(pos <= sz, std::__throw_out_of_range, "");
1408 procrustes(n, sz - pos);
1409 return assign(str.data() + pos, n);
1412 basic_fbstring& assign(const value_type* s, const size_type n) {
1413 Invariant checker(*this);
1416 std::copy(s, s + n, begin());
1418 assert(size() == n);
1420 const value_type *const s2 = s + size();
1421 std::copy(s, s2, begin());
1422 append(s2, n - size());
1423 assert(size() == n);
1425 store_.writeTerminator();
1426 assert(size() == n);
1430 basic_fbstring& assign(const value_type* s) {
1431 return assign(s, traits_type::length(s));
1434 basic_fbstring& assign(std::initializer_list<value_type> il) {
1435 return assign(il.begin(), il.end());
1438 template <class ItOrLength, class ItOrChar>
1439 basic_fbstring& assign(ItOrLength first_or_n, ItOrChar last_or_c) {
1440 return replace(begin(), end(), first_or_n, last_or_c);
1443 basic_fbstring& insert(size_type pos1, const basic_fbstring& str) {
1444 return insert(pos1, str.data(), str.size());
1447 basic_fbstring& insert(size_type pos1, const basic_fbstring& str,
1448 size_type pos2, size_type n) {
1449 enforce(pos2 <= str.length(), std::__throw_out_of_range, "");
1450 procrustes(n, str.length() - pos2);
1451 return insert(pos1, str.data() + pos2, n);
1454 basic_fbstring& insert(size_type pos, const value_type* s, size_type n) {
1455 enforce(pos <= length(), std::__throw_out_of_range, "");
1456 insert(begin() + pos, s, s + n);
1460 basic_fbstring& insert(size_type pos, const value_type* s) {
1461 return insert(pos, s, traits_type::length(s));
1464 basic_fbstring& insert(size_type pos, size_type n, value_type c) {
1465 enforce(pos <= length(), std::__throw_out_of_range, "");
1466 insert(begin() + pos, n, c);
1470 iterator insert(const_iterator p, const value_type c) {
1471 const size_type pos = p - begin();
1473 return begin() + pos;
1477 template <int i> class Selector {};
1479 iterator insertImplDiscr(const_iterator p,
1480 size_type n, value_type c, Selector<1>) {
1481 Invariant checker(*this);
1483 auto const pos = p - begin();
1484 assert(p >= begin() && p <= end());
1485 if (capacity() - size() < n) {
1486 const size_type sz = p - begin();
1487 reserve(size() + n);
1490 const iterator oldEnd = end();
1491 if (n < size_type(oldEnd - p)) {
1492 append(oldEnd - n, oldEnd);
1494 // reverse_iterator(oldEnd - n),
1495 // reverse_iterator(p),
1496 // reverse_iterator(oldEnd));
1497 fbstring_detail::pod_move(&*p, &*oldEnd - n,
1499 std::fill(begin() + pos, begin() + pos + n, c);
1501 append(n - (end() - p), c);
1502 append(iterator(p), oldEnd);
1503 std::fill(iterator(p), oldEnd, c);
1505 store_.writeTerminator();
1506 return begin() + pos;
1509 template<class InputIter>
1510 iterator insertImplDiscr(const_iterator i,
1511 InputIter b, InputIter e, Selector<0>) {
1512 return insertImpl(i, b, e,
1513 typename std::iterator_traits<InputIter>::iterator_category());
1516 template <class FwdIterator>
1517 iterator insertImpl(const_iterator i,
1518 FwdIterator s1, FwdIterator s2, std::forward_iterator_tag) {
1519 Invariant checker(*this);
1521 const size_type pos = i - begin();
1522 const typename std::iterator_traits<FwdIterator>::difference_type n2 =
1523 std::distance(s1, s2);
1525 using namespace fbstring_detail;
1526 assert(pos <= size());
1528 const typename std::iterator_traits<FwdIterator>::difference_type maxn2 =
1529 capacity() - size();
1531 // realloc the string
1532 reserve(size() + n2);
1535 if (pos + n2 <= size()) {
1536 const iterator tailBegin = end() - n2;
1537 store_.expand_noinit(n2);
1538 fbstring_detail::pod_copy(tailBegin, tailBegin + n2, end() - n2);
1539 std::copy(const_reverse_iterator(tailBegin), const_reverse_iterator(i),
1540 reverse_iterator(tailBegin + n2));
1541 std::copy(s1, s2, begin() + pos);
1544 const size_type old_size = size();
1545 std::advance(t, old_size - pos);
1546 const size_t newElems = std::distance(t, s2);
1547 store_.expand_noinit(n2);
1548 std::copy(t, s2, begin() + old_size);
1549 fbstring_detail::pod_copy(data() + pos, data() + old_size,
1550 begin() + old_size + newElems);
1551 std::copy(s1, t, begin() + pos);
1553 store_.writeTerminator();
1554 return begin() + pos;
1557 template <class InputIterator>
1558 iterator insertImpl(const_iterator i,
1559 InputIterator b, InputIterator e,
1560 std::input_iterator_tag) {
1561 const auto pos = i - begin();
1562 basic_fbstring temp(begin(), i);
1563 for (; b != e; ++b) {
1566 temp.append(i, cend());
1568 return begin() + pos;
1572 template <class ItOrLength, class ItOrChar>
1573 iterator insert(const_iterator p, ItOrLength first_or_n, ItOrChar last_or_c) {
1574 Selector<std::numeric_limits<ItOrLength>::is_specialized> sel;
1575 return insertImplDiscr(p, first_or_n, last_or_c, sel);
1578 iterator insert(const_iterator p, std::initializer_list<value_type> il) {
1579 return insert(p, il.begin(), il.end());
1582 basic_fbstring& erase(size_type pos = 0, size_type n = npos) {
1583 Invariant checker(*this);
1585 enforce(pos <= length(), std::__throw_out_of_range, "");
1586 procrustes(n, length() - pos);
1587 std::copy(begin() + pos + n, end(), begin() + pos);
1588 resize(length() - n);
1592 iterator erase(iterator position) {
1593 const size_type pos(position - begin());
1594 enforce(pos <= size(), std::__throw_out_of_range, "");
1596 return begin() + pos;
1599 iterator erase(iterator first, iterator last) {
1600 const size_type pos(first - begin());
1601 erase(pos, last - first);
1602 return begin() + pos;
1605 // Replaces at most n1 chars of *this, starting with pos1 with the
1607 basic_fbstring& replace(size_type pos1, size_type n1,
1608 const basic_fbstring& str) {
1609 return replace(pos1, n1, str.data(), str.size());
1612 // Replaces at most n1 chars of *this, starting with pos1,
1613 // with at most n2 chars of str starting with pos2
1614 basic_fbstring& replace(size_type pos1, size_type n1,
1615 const basic_fbstring& str,
1616 size_type pos2, size_type n2) {
1617 enforce(pos2 <= str.length(), std::__throw_out_of_range, "");
1618 return replace(pos1, n1, str.data() + pos2,
1619 std::min(n2, str.size() - pos2));
1622 // Replaces at most n1 chars of *this, starting with pos, with chars from s
1623 basic_fbstring& replace(size_type pos, size_type n1, const value_type* s) {
1624 return replace(pos, n1, s, traits_type::length(s));
1627 // Replaces at most n1 chars of *this, starting with pos, with n2
1630 // consolidated with
1632 // Replaces at most n1 chars of *this, starting with pos, with at
1633 // most n2 chars of str. str must have at least n2 chars.
1634 template <class StrOrLength, class NumOrChar>
1635 basic_fbstring& replace(size_type pos, size_type n1,
1636 StrOrLength s_or_n2, NumOrChar n_or_c) {
1637 Invariant checker(*this);
1639 enforce(pos <= size(), std::__throw_out_of_range, "");
1640 procrustes(n1, length() - pos);
1641 const iterator b = begin() + pos;
1642 return replace(b, b + n1, s_or_n2, n_or_c);
1645 basic_fbstring& replace(iterator i1, iterator i2, const basic_fbstring& str) {
1646 return replace(i1, i2, str.data(), str.length());
1649 basic_fbstring& replace(iterator i1, iterator i2, const value_type* s) {
1650 return replace(i1, i2, s, traits_type::length(s));
1654 basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
1655 const value_type* s, size_type n,
1658 assert(begin() <= i1 && i1 <= end());
1659 assert(begin() <= i2 && i2 <= end());
1660 return replace(i1, i2, s, s + n);
1663 basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
1664 size_type n2, value_type c, Selector<1>) {
1665 const size_type n1 = i2 - i1;
1667 std::fill(i1, i1 + n2, c);
1670 std::fill(i1, i2, c);
1671 insert(i2, n2 - n1, c);
1677 template <class InputIter>
1678 basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
1679 InputIter b, InputIter e,
1681 replaceImpl(i1, i2, b, e,
1682 typename std::iterator_traits<InputIter>::iterator_category());
1687 template <class FwdIterator>
1688 bool replaceAliased(iterator /* i1 */,
1690 FwdIterator /* s1 */,
1691 FwdIterator /* s2 */,
1696 template <class FwdIterator>
1697 bool replaceAliased(iterator i1, iterator i2,
1698 FwdIterator s1, FwdIterator s2, std::true_type) {
1699 static const std::less_equal<const value_type*> le =
1700 std::less_equal<const value_type*>();
1701 const bool aliased = le(&*begin(), &*s1) && le(&*s1, &*end());
1705 // Aliased replace, copy to new string
1706 basic_fbstring temp;
1707 temp.reserve(size() - (i2 - i1) + std::distance(s1, s2));
1708 temp.append(begin(), i1).append(s1, s2).append(i2, end());
1713 template <class FwdIterator>
1714 void replaceImpl(iterator i1, iterator i2,
1715 FwdIterator s1, FwdIterator s2, std::forward_iterator_tag) {
1716 Invariant checker(*this);
1719 // Handle aliased replace
1720 if (replaceAliased(i1, i2, s1, s2,
1721 std::integral_constant<bool,
1722 std::is_same<FwdIterator, iterator>::value ||
1723 std::is_same<FwdIterator, const_iterator>::value>())) {
1727 auto const n1 = i2 - i1;
1729 auto const n2 = std::distance(s1, s2);
1734 std::copy(s1, s2, i1);
1738 fbstring_detail::copy_n(s1, n1, i1);
1739 std::advance(s1, n1);
1745 template <class InputIterator>
1746 void replaceImpl(iterator i1, iterator i2,
1747 InputIterator b, InputIterator e, std::input_iterator_tag) {
1748 basic_fbstring temp(begin(), i1);
1749 temp.append(b, e).append(i2, end());
1754 template <class T1, class T2>
1755 basic_fbstring& replace(iterator i1, iterator i2,
1756 T1 first_or_n_or_s, T2 last_or_c_or_n) {
1758 num1 = std::numeric_limits<T1>::is_specialized,
1759 num2 = std::numeric_limits<T2>::is_specialized;
1760 return replaceImplDiscr(
1761 i1, i2, first_or_n_or_s, last_or_c_or_n,
1762 Selector<num1 ? (num2 ? 1 : -1) : (num2 ? 2 : 0)>());
1765 size_type copy(value_type* s, size_type n, size_type pos = 0) const {
1766 enforce(pos <= size(), std::__throw_out_of_range, "");
1767 procrustes(n, size() - pos);
1769 fbstring_detail::pod_copy(
1776 void swap(basic_fbstring& rhs) {
1777 store_.swap(rhs.store_);
1780 const value_type* c_str() const {
1781 return store_.c_str();
1784 const value_type* data() const { return c_str(); }
1786 allocator_type get_allocator() const {
1787 return allocator_type();
1790 size_type find(const basic_fbstring& str, size_type pos = 0) const {
1791 return find(str.data(), pos, str.length());
1794 size_type find(const value_type* needle, const size_type pos,
1795 const size_type nsize) const {
1796 if (!nsize) return pos;
1797 auto const size = this->size();
1798 // nsize + pos can overflow (eg pos == npos), guard against that by checking
1799 // that nsize + pos does not wrap around.
1800 if (nsize + pos > size || nsize + pos < pos) return npos;
1801 // Don't use std::search, use a Boyer-Moore-like trick by comparing
1802 // the last characters first
1803 auto const haystack = data();
1804 auto const nsize_1 = nsize - 1;
1805 auto const lastNeedle = needle[nsize_1];
1807 // Boyer-Moore skip value for the last char in the needle. Zero is
1808 // not a valid value; skip will be computed the first time it's
1812 const E * i = haystack + pos;
1813 auto iEnd = haystack + size - nsize_1;
1816 // Boyer-Moore: match the last element in the needle
1817 while (i[nsize_1] != lastNeedle) {
1823 // Here we know that the last char matches
1824 // Continue in pedestrian mode
1825 for (size_t j = 0; ; ) {
1827 if (i[j] != needle[j]) {
1828 // Not found, we can skip
1829 // Compute the skip value lazily
1832 while (skip <= nsize_1 && needle[nsize_1 - skip] != lastNeedle) {
1839 // Check if done searching
1842 return i - haystack;
1849 size_type find(const value_type* s, size_type pos = 0) const {
1850 return find(s, pos, traits_type::length(s));
1853 size_type find (value_type c, size_type pos = 0) const {
1854 return find(&c, pos, 1);
1857 size_type rfind(const basic_fbstring& str, size_type pos = npos) const {
1858 return rfind(str.data(), pos, str.length());
1861 size_type rfind(const value_type* s, size_type pos, size_type n) const {
1862 if (n > length()) return npos;
1863 pos = std::min(pos, length() - n);
1864 if (n == 0) return pos;
1866 const_iterator i(begin() + pos);
1868 if (traits_type::eq(*i, *s)
1869 && traits_type::compare(&*i, s, n) == 0) {
1872 if (i == begin()) break;
1877 size_type rfind(const value_type* s, size_type pos = npos) const {
1878 return rfind(s, pos, traits_type::length(s));
1881 size_type rfind(value_type c, size_type pos = npos) const {
1882 return rfind(&c, pos, 1);
1885 size_type find_first_of(const basic_fbstring& str, size_type pos = 0) const {
1886 return find_first_of(str.data(), pos, str.length());
1889 size_type find_first_of(const value_type* s,
1890 size_type pos, size_type n) const {
1891 if (pos > length() || n == 0) return npos;
1892 const_iterator i(begin() + pos),
1894 for (; i != finish; ++i) {
1895 if (traits_type::find(s, n, *i) != 0) {
1902 size_type find_first_of(const value_type* s, size_type pos = 0) const {
1903 return find_first_of(s, pos, traits_type::length(s));
1906 size_type find_first_of(value_type c, size_type pos = 0) const {
1907 return find_first_of(&c, pos, 1);
1910 size_type find_last_of (const basic_fbstring& str,
1911 size_type pos = npos) const {
1912 return find_last_of(str.data(), pos, str.length());
1915 size_type find_last_of (const value_type* s, size_type pos,
1916 size_type n) const {
1917 if (!empty() && n > 0) {
1918 pos = std::min(pos, length() - 1);
1919 const_iterator i(begin() + pos);
1921 if (traits_type::find(s, n, *i) != 0) {
1924 if (i == begin()) break;
1930 size_type find_last_of (const value_type* s,
1931 size_type pos = npos) const {
1932 return find_last_of(s, pos, traits_type::length(s));
1935 size_type find_last_of (value_type c, size_type pos = npos) const {
1936 return find_last_of(&c, pos, 1);
1939 size_type find_first_not_of(const basic_fbstring& str,
1940 size_type pos = 0) const {
1941 return find_first_not_of(str.data(), pos, str.size());
1944 size_type find_first_not_of(const value_type* s, size_type pos,
1945 size_type n) const {
1946 if (pos < length()) {
1950 for (; i != finish; ++i) {
1951 if (traits_type::find(s, n, *i) == 0) {
1959 size_type find_first_not_of(const value_type* s,
1960 size_type pos = 0) const {
1961 return find_first_not_of(s, pos, traits_type::length(s));
1964 size_type find_first_not_of(value_type c, size_type pos = 0) const {
1965 return find_first_not_of(&c, pos, 1);
1968 size_type find_last_not_of(const basic_fbstring& str,
1969 size_type pos = npos) const {
1970 return find_last_not_of(str.data(), pos, str.length());
1973 size_type find_last_not_of(const value_type* s, size_type pos,
1974 size_type n) const {
1975 if (!this->empty()) {
1976 pos = std::min(pos, size() - 1);
1977 const_iterator i(begin() + pos);
1979 if (traits_type::find(s, n, *i) == 0) {
1982 if (i == begin()) break;
1988 size_type find_last_not_of(const value_type* s,
1989 size_type pos = npos) const {
1990 return find_last_not_of(s, pos, traits_type::length(s));
1993 size_type find_last_not_of (value_type c, size_type pos = npos) const {
1994 return find_last_not_of(&c, pos, 1);
1997 basic_fbstring substr(size_type pos = 0, size_type n = npos) const& {
1998 enforce(pos <= size(), std::__throw_out_of_range, "");
1999 return basic_fbstring(data() + pos, std::min(n, size() - pos));
2002 basic_fbstring substr(size_type pos = 0, size_type n = npos) && {
2003 enforce(pos <= size(), std::__throw_out_of_range, "");
2005 if (n < size()) resize(n);
2006 return std::move(*this);
2009 int compare(const basic_fbstring& str) const {
2010 // FIX due to Goncalo N M de Carvalho July 18, 2005
2011 return compare(0, size(), str);
2014 int compare(size_type pos1, size_type n1,
2015 const basic_fbstring& str) const {
2016 return compare(pos1, n1, str.data(), str.size());
2019 int compare(size_type pos1, size_type n1,
2020 const value_type* s) const {
2021 return compare(pos1, n1, s, traits_type::length(s));
2024 int compare(size_type pos1, size_type n1,
2025 const value_type* s, size_type n2) const {
2026 enforce(pos1 <= size(), std::__throw_out_of_range, "");
2027 procrustes(n1, size() - pos1);
2028 // The line below fixed by Jean-Francois Bastien, 04-23-2007. Thanks!
2029 const int r = traits_type::compare(pos1 + data(), s, std::min(n1, n2));
2030 return r != 0 ? r : n1 > n2 ? 1 : n1 < n2 ? -1 : 0;
2033 int compare(size_type pos1, size_type n1,
2034 const basic_fbstring& str,
2035 size_type pos2, size_type n2) const {
2036 enforce(pos2 <= str.size(), std::__throw_out_of_range, "");
2037 return compare(pos1, n1, str.data() + pos2,
2038 std::min(n2, str.size() - pos2));
2041 // Code from Jean-Francois Bastien (03/26/2007)
2042 int compare(const value_type* s) const {
2043 // Could forward to compare(0, size(), s, traits_type::length(s))
2044 // but that does two extra checks
2045 const size_type n1(size()), n2(traits_type::length(s));
2046 const int r = traits_type::compare(data(), s, std::min(n1, n2));
2047 return r != 0 ? r : n1 > n2 ? 1 : n1 < n2 ? -1 : 0;
2055 // non-member functions
2057 template <typename E, class T, class A, class S>
2059 basic_fbstring<E, T, A, S> operator+(const basic_fbstring<E, T, A, S>& lhs,
2060 const basic_fbstring<E, T, A, S>& rhs) {
2062 basic_fbstring<E, T, A, S> result;
2063 result.reserve(lhs.size() + rhs.size());
2064 result.append(lhs).append(rhs);
2065 return std::move(result);
2069 template <typename E, class T, class A, class S>
2071 basic_fbstring<E, T, A, S> operator+(basic_fbstring<E, T, A, S>&& lhs,
2072 const basic_fbstring<E, T, A, S>& rhs) {
2073 return std::move(lhs.append(rhs));
2077 template <typename E, class T, class A, class S>
2079 basic_fbstring<E, T, A, S> operator+(const basic_fbstring<E, T, A, S>& lhs,
2080 basic_fbstring<E, T, A, S>&& rhs) {
2081 if (rhs.capacity() >= lhs.size() + rhs.size()) {
2082 // Good, at least we don't need to reallocate
2083 return std::move(rhs.insert(0, lhs));
2085 // Meh, no go. Forward to operator+(const&, const&).
2086 auto const& rhsC = rhs;
2091 template <typename E, class T, class A, class S>
2093 basic_fbstring<E, T, A, S> operator+(basic_fbstring<E, T, A, S>&& lhs,
2094 basic_fbstring<E, T, A, S>&& rhs) {
2095 return std::move(lhs.append(rhs));
2099 template <typename E, class T, class A, class S>
2101 basic_fbstring<E, T, A, S> operator+(
2103 const basic_fbstring<E, T, A, S>& rhs) {
2105 basic_fbstring<E, T, A, S> result;
2106 const auto len = basic_fbstring<E, T, A, S>::traits_type::length(lhs);
2107 result.reserve(len + rhs.size());
2108 result.append(lhs, len).append(rhs);
2113 template <typename E, class T, class A, class S>
2115 basic_fbstring<E, T, A, S> operator+(
2117 basic_fbstring<E, T, A, S>&& rhs) {
2119 const auto len = basic_fbstring<E, T, A, S>::traits_type::length(lhs);
2120 if (rhs.capacity() >= len + rhs.size()) {
2121 // Good, at least we don't need to reallocate
2122 rhs.insert(rhs.begin(), lhs, lhs + len);
2125 // Meh, no go. Do it by hand since we have len already.
2126 basic_fbstring<E, T, A, S> result;
2127 result.reserve(len + rhs.size());
2128 result.append(lhs, len).append(rhs);
2133 template <typename E, class T, class A, class S>
2135 basic_fbstring<E, T, A, S> operator+(
2137 const basic_fbstring<E, T, A, S>& rhs) {
2139 basic_fbstring<E, T, A, S> result;
2140 result.reserve(1 + rhs.size());
2141 result.push_back(lhs);
2147 template <typename E, class T, class A, class S>
2149 basic_fbstring<E, T, A, S> operator+(
2151 basic_fbstring<E, T, A, S>&& rhs) {
2153 if (rhs.capacity() > rhs.size()) {
2154 // Good, at least we don't need to reallocate
2155 rhs.insert(rhs.begin(), lhs);
2158 // Meh, no go. Forward to operator+(E, const&).
2159 auto const& rhsC = rhs;
2164 template <typename E, class T, class A, class S>
2166 basic_fbstring<E, T, A, S> operator+(
2167 const basic_fbstring<E, T, A, S>& lhs,
2170 typedef typename basic_fbstring<E, T, A, S>::size_type size_type;
2171 typedef typename basic_fbstring<E, T, A, S>::traits_type traits_type;
2173 basic_fbstring<E, T, A, S> result;
2174 const size_type len = traits_type::length(rhs);
2175 result.reserve(lhs.size() + len);
2176 result.append(lhs).append(rhs, len);
2180 // C++11 21.4.8.1/10
2181 template <typename E, class T, class A, class S>
2183 basic_fbstring<E, T, A, S> operator+(
2184 basic_fbstring<E, T, A, S>&& lhs,
2187 return std::move(lhs += rhs);
2190 // C++11 21.4.8.1/11
2191 template <typename E, class T, class A, class S>
2193 basic_fbstring<E, T, A, S> operator+(
2194 const basic_fbstring<E, T, A, S>& lhs,
2197 basic_fbstring<E, T, A, S> result;
2198 result.reserve(lhs.size() + 1);
2200 result.push_back(rhs);
2204 // C++11 21.4.8.1/12
2205 template <typename E, class T, class A, class S>
2207 basic_fbstring<E, T, A, S> operator+(
2208 basic_fbstring<E, T, A, S>&& lhs,
2211 return std::move(lhs += rhs);
2214 template <typename E, class T, class A, class S>
2216 bool operator==(const basic_fbstring<E, T, A, S>& lhs,
2217 const basic_fbstring<E, T, A, S>& rhs) {
2218 return lhs.size() == rhs.size() && lhs.compare(rhs) == 0; }
2220 template <typename E, class T, class A, class S>
2222 bool operator==(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2223 const basic_fbstring<E, T, A, S>& rhs) {
2224 return rhs == lhs; }
2226 template <typename E, class T, class A, class S>
2228 bool operator==(const basic_fbstring<E, T, A, S>& lhs,
2229 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2230 return lhs.compare(rhs) == 0; }
2232 template <typename E, class T, class A, class S>
2234 bool operator!=(const basic_fbstring<E, T, A, S>& lhs,
2235 const basic_fbstring<E, T, A, S>& rhs) {
2236 return !(lhs == rhs); }
2238 template <typename E, class T, class A, class S>
2240 bool operator!=(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2241 const basic_fbstring<E, T, A, S>& rhs) {
2242 return !(lhs == rhs); }
2244 template <typename E, class T, class A, class S>
2246 bool operator!=(const basic_fbstring<E, T, A, S>& lhs,
2247 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2248 return !(lhs == rhs); }
2250 template <typename E, class T, class A, class S>
2252 bool operator<(const basic_fbstring<E, T, A, S>& lhs,
2253 const basic_fbstring<E, T, A, S>& rhs) {
2254 return lhs.compare(rhs) < 0; }
2256 template <typename E, class T, class A, class S>
2258 bool operator<(const basic_fbstring<E, T, A, S>& lhs,
2259 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2260 return lhs.compare(rhs) < 0; }
2262 template <typename E, class T, class A, class S>
2264 bool operator<(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2265 const basic_fbstring<E, T, A, S>& rhs) {
2266 return rhs.compare(lhs) > 0; }
2268 template <typename E, class T, class A, class S>
2270 bool operator>(const basic_fbstring<E, T, A, S>& lhs,
2271 const basic_fbstring<E, T, A, S>& rhs) {
2274 template <typename E, class T, class A, class S>
2276 bool operator>(const basic_fbstring<E, T, A, S>& lhs,
2277 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2280 template <typename E, class T, class A, class S>
2282 bool operator>(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2283 const basic_fbstring<E, T, A, S>& rhs) {
2286 template <typename E, class T, class A, class S>
2288 bool operator<=(const basic_fbstring<E, T, A, S>& lhs,
2289 const basic_fbstring<E, T, A, S>& rhs) {
2290 return !(rhs < lhs); }
2292 template <typename E, class T, class A, class S>
2294 bool operator<=(const basic_fbstring<E, T, A, S>& lhs,
2295 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2296 return !(rhs < lhs); }
2298 template <typename E, class T, class A, class S>
2300 bool operator<=(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2301 const basic_fbstring<E, T, A, S>& rhs) {
2302 return !(rhs < lhs); }
2304 template <typename E, class T, class A, class S>
2306 bool operator>=(const basic_fbstring<E, T, A, S>& lhs,
2307 const basic_fbstring<E, T, A, S>& rhs) {
2308 return !(lhs < rhs); }
2310 template <typename E, class T, class A, class S>
2312 bool operator>=(const basic_fbstring<E, T, A, S>& lhs,
2313 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2314 return !(lhs < rhs); }
2316 template <typename E, class T, class A, class S>
2318 bool operator>=(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2319 const basic_fbstring<E, T, A, S>& rhs) {
2320 return !(lhs < rhs);
2324 template <typename E, class T, class A, class S>
2325 void swap(basic_fbstring<E, T, A, S>& lhs, basic_fbstring<E, T, A, S>& rhs) {
2329 // TODO: make this faster.
2330 template <typename E, class T, class A, class S>
2333 typename basic_fbstring<E, T, A, S>::value_type,
2334 typename basic_fbstring<E, T, A, S>::traits_type>&
2336 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2337 typename basic_fbstring<E, T, A, S>::traits_type>& is,
2338 basic_fbstring<E, T, A, S>& str) {
2339 typename std::basic_istream<E, T>::sentry sentry(is);
2340 typedef std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2341 typename basic_fbstring<E, T, A, S>::traits_type>
2343 typedef typename __istream_type::ios_base __ios_base;
2344 size_t extracted = 0;
2345 auto err = __ios_base::goodbit;
2347 auto n = is.width();
2352 for (auto got = is.rdbuf()->sgetc(); extracted != size_t(n); ++extracted) {
2353 if (got == T::eof()) {
2354 err |= __ios_base::eofbit;
2358 if (isspace(got)) break;
2360 got = is.rdbuf()->snextc();
2364 err |= __ios_base::failbit;
2372 template <typename E, class T, class A, class S>
2374 std::basic_ostream<typename basic_fbstring<E, T, A, S>::value_type,
2375 typename basic_fbstring<E, T, A, S>::traits_type>&
2377 std::basic_ostream<typename basic_fbstring<E, T, A, S>::value_type,
2378 typename basic_fbstring<E, T, A, S>::traits_type>& os,
2379 const basic_fbstring<E, T, A, S>& str) {
2381 typename std::basic_ostream<
2382 typename basic_fbstring<E, T, A, S>::value_type,
2383 typename basic_fbstring<E, T, A, S>::traits_type>::sentry __s(os);
2385 typedef std::ostreambuf_iterator<
2386 typename basic_fbstring<E, T, A, S>::value_type,
2387 typename basic_fbstring<E, T, A, S>::traits_type> _Ip;
2388 size_t __len = str.size();
2390 (os.flags() & std::ios_base::adjustfield) == std::ios_base::left;
2391 if (__pad_and_output(_Ip(os),
2393 __left ? str.data() + __len : str.data(),
2396 os.fill()).failed()) {
2397 os.setstate(std::ios_base::badbit | std::ios_base::failbit);
2400 #elif defined(_MSC_VER)
2401 // MSVC doesn't define __ostream_insert
2402 os.write(str.data(), str.size());
2404 std::__ostream_insert(os, str.data(), str.size());
2409 #ifndef _LIBSTDCXX_FBSTRING
2411 template <typename E, class T, class A, class S>
2413 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2414 typename basic_fbstring<E, T, A, S>::traits_type>&
2416 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2417 typename basic_fbstring<E, T, A, S>::traits_type>& is,
2418 basic_fbstring<E, T, A, S>& str,
2419 typename basic_fbstring<E, T, A, S>::value_type delim) {
2420 // Use the nonstandard getdelim()
2421 char * buf = nullptr;
2424 // This looks quadratic but it really depends on realloc
2425 auto const newSize = size + 128;
2426 buf = static_cast<char*>(checkedRealloc(buf, newSize));
2427 is.getline(buf + size, newSize - size, delim);
2428 if (is.bad() || is.eof() || !is.fail()) {
2429 // done by either failure, end of file, or normal read
2430 size += std::strlen(buf + size);
2433 // Here we have failed due to too short a buffer
2434 // Minus one to discount the terminating '\0'
2436 assert(buf[size] == 0);
2437 // Clear the error so we can continue reading
2440 basic_fbstring<E, T, A, S> result(buf, size, size + 1,
2441 AcquireMallocatedString());
2446 template <typename E, class T, class A, class S>
2448 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2449 typename basic_fbstring<E, T, A, S>::traits_type>&
2451 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2452 typename basic_fbstring<E, T, A, S>::traits_type>& is,
2453 basic_fbstring<E, T, A, S>& str) {
2454 // Just forward to the version with a delimiter
2455 return getline(is, str, '\n');
2460 template <typename E1, class T, class A, class S>
2461 const typename basic_fbstring<E1, T, A, S>::size_type
2462 basic_fbstring<E1, T, A, S>::npos =
2463 static_cast<typename basic_fbstring<E1, T, A, S>::size_type>(-1);
2465 #ifndef _LIBSTDCXX_FBSTRING
2466 // basic_string compatibility routines
2468 template <typename E, class T, class A, class S>
2470 bool operator==(const basic_fbstring<E, T, A, S>& lhs,
2471 const std::string& rhs) {
2472 return lhs.compare(0, lhs.size(), rhs.data(), rhs.size()) == 0;
2475 template <typename E, class T, class A, class S>
2477 bool operator==(const std::string& lhs,
2478 const basic_fbstring<E, T, A, S>& rhs) {
2482 template <typename E, class T, class A, class S>
2484 bool operator!=(const basic_fbstring<E, T, A, S>& lhs,
2485 const std::string& rhs) {
2486 return !(lhs == rhs);
2489 template <typename E, class T, class A, class S>
2491 bool operator!=(const std::string& lhs,
2492 const basic_fbstring<E, T, A, S>& rhs) {
2493 return !(lhs == rhs);
2496 #if !defined(_LIBSTDCXX_FBSTRING)
2497 typedef basic_fbstring<char> fbstring;
2500 // fbstring is relocatable
2501 template <class T, class R, class A, class S>
2502 FOLLY_ASSUME_RELOCATABLE(basic_fbstring<T, R, A, S>);
2505 _GLIBCXX_END_NAMESPACE_VERSION
2508 } // namespace folly
2510 #ifndef _LIBSTDCXX_FBSTRING
2512 // Hash functions to make fbstring usable with e.g. hash_map
2514 // Handle interaction with different C++ standard libraries, which
2515 // expect these types to be in different namespaces.
2517 #define FOLLY_FBSTRING_HASH1(T) \
2519 struct hash< ::folly::basic_fbstring<T> > { \
2520 size_t operator()(const ::folly::fbstring& s) const { \
2521 return ::folly::hash::fnv32_buf(s.data(), s.size()); \
2525 // The C++11 standard says that these four are defined
2526 #define FOLLY_FBSTRING_HASH \
2527 FOLLY_FBSTRING_HASH1(char) \
2528 FOLLY_FBSTRING_HASH1(char16_t) \
2529 FOLLY_FBSTRING_HASH1(char32_t) \
2530 FOLLY_FBSTRING_HASH1(wchar_t)
2538 #if FOLLY_HAVE_DEPRECATED_ASSOC
2539 #if defined(_GLIBCXX_SYMVER) && !defined(__BIONIC__)
2540 namespace __gnu_cxx {
2544 } // namespace __gnu_cxx
2545 #endif // _GLIBCXX_SYMVER && !__BIONIC__
2546 #endif // FOLLY_HAVE_DEPRECATED_ASSOC
2548 #undef FOLLY_FBSTRING_HASH
2549 #undef FOLLY_FBSTRING_HASH1
2551 #endif // _LIBSTDCXX_FBSTRING
2553 #pragma GCC diagnostic pop
2555 #undef FBSTRING_DISABLE_ADDRESS_SANITIZER
2557 #undef FBSTRING_LIKELY
2558 #undef FBSTRING_UNLIKELY
2560 #ifdef FOLLY_DEFINED_NDEBUG_FOR_FBSTRING
2562 #undef FOLLY_DEFINED_NDEBUG_FOR_FBSTRING
2563 #endif // FOLLY_DEFINED_NDEBUG_FOR_FBSTRING
2565 #endif // FOLLY_BASE_FBSTRING_H_