diff options
Diffstat (limited to 'third_party/abseil-cpp/absl/strings/string_view.h')
| -rw-r--r-- | third_party/abseil-cpp/absl/strings/string_view.h | 198 |
1 files changed, 55 insertions, 143 deletions
diff --git a/third_party/abseil-cpp/absl/strings/string_view.h b/third_party/abseil-cpp/absl/strings/string_view.h index a4c9a6526c..1861ea62a9 100644 --- a/third_party/abseil-cpp/absl/strings/string_view.h +++ b/third_party/abseil-cpp/absl/strings/string_view.h @@ -36,7 +36,6 @@ #include <limits> #include <string> -#include "absl/base/attributes.h" #include "absl/base/config.h" #include "absl/base/internal/throw_delegate.h" #include "absl/base/macros.h" @@ -49,7 +48,7 @@ namespace absl { ABSL_NAMESPACE_BEGIN -using string_view = std::string_view; +using std::string_view; ABSL_NAMESPACE_END } // namespace absl @@ -62,12 +61,6 @@ ABSL_NAMESPACE_END #define ABSL_INTERNAL_STRING_VIEW_MEMCMP memcmp #endif // ABSL_HAVE_BUILTIN(__builtin_memcmp) -#if defined(__cplusplus) && __cplusplus >= 201402L -#define ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR constexpr -#else -#define ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR -#endif - namespace absl { ABSL_NAMESPACE_BEGIN @@ -118,11 +111,6 @@ ABSL_NAMESPACE_BEGIN // example, when splitting a string, `std::vector<absl::string_view>` is a // natural data type for the output. // -// For another example, a Cord is a non-contiguous, potentially very -// long string-like object. The Cord class has an interface that iteratively -// provides string_view objects that point to the successive pieces of a Cord -// object. -// // When constructed from a source which is NUL-terminated, the `string_view` // itself will not include the NUL-terminator unless a specific size (including // the NUL) is passed to the constructor. As a result, common idioms that work @@ -187,20 +175,18 @@ class string_view { template <typename Allocator> string_view( // NOLINT(runtime/explicit) - const std::basic_string<char, std::char_traits<char>, Allocator>& str - ABSL_ATTRIBUTE_LIFETIME_BOUND) noexcept + const std::basic_string<char, std::char_traits<char>, Allocator>& + str) noexcept // This is implemented in terms of `string_view(p, n)` so `str.size()` // doesn't need to be reevaluated after `ptr_` is set. - // The length check is also skipped since it is unnecessary and causes - // code bloat. - : string_view(str.data(), str.size(), SkipCheckLengthTag{}) {} + : string_view(str.data(), str.size()) {} // Implicit constructor of a `string_view` from NUL-terminated `str`. When // accepting possibly null strings, use `absl::NullSafeStringView(str)` // instead (see below). - // The length check is skipped since it is unnecessary and causes code bloat. constexpr string_view(const char* str) // NOLINT(runtime/explicit) - : ptr_(str), length_(str ? StrlenInternal(str) : 0) {} + : ptr_(str), + length_(str ? CheckLengthInternal(StrlenInternal(str)) : 0) {} // Implicit constructor of a `string_view` from a `const char*` and length. constexpr string_view(const char* data, size_type len) @@ -273,7 +259,9 @@ class string_view { // string_view::size() // // Returns the number of characters in the `string_view`. - constexpr size_type size() const noexcept { return length_; } + constexpr size_type size() const noexcept { + return length_; + } // string_view::length() // @@ -295,7 +283,7 @@ class string_view { // Returns the ith element of the `string_view` using the array operator. // Note that this operator does not perform any bounds checking. constexpr const_reference operator[](size_type i) const { - return ABSL_HARDENING_ASSERT(i < size()), ptr_[i]; + return ABSL_ASSERT(i < size()), ptr_[i]; } // string_view::at() @@ -315,14 +303,14 @@ class string_view { // // Returns the first element of a `string_view`. constexpr const_reference front() const { - return ABSL_HARDENING_ASSERT(!empty()), ptr_[0]; + return ABSL_ASSERT(!empty()), ptr_[0]; } // string_view::back() // // Returns the last element of a `string_view`. constexpr const_reference back() const { - return ABSL_HARDENING_ASSERT(!empty()), ptr_[size() - 1]; + return ABSL_ASSERT(!empty()), ptr_[size() - 1]; } // string_view::data() @@ -331,7 +319,7 @@ class string_view { // stored elsewhere). Note that `string_view::data()` may contain embedded nul // characters, but the returned buffer may or may not be NUL-terminated; // therefore, do not pass `data()` to a routine that expects a NUL-terminated - // string. + // std::string. constexpr const_pointer data() const noexcept { return ptr_; } // Modifiers @@ -339,9 +327,9 @@ class string_view { // string_view::remove_prefix() // // Removes the first `n` characters from the `string_view`. Note that the - // underlying string is not changed, only the view. - ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR void remove_prefix(size_type n) { - ABSL_HARDENING_ASSERT(n <= length_); + // underlying std::string is not changed, only the view. + void remove_prefix(size_type n) { + assert(n <= length_); ptr_ += n; length_ -= n; } @@ -349,16 +337,16 @@ class string_view { // string_view::remove_suffix() // // Removes the last `n` characters from the `string_view`. Note that the - // underlying string is not changed, only the view. - ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR void remove_suffix(size_type n) { - ABSL_HARDENING_ASSERT(n <= length_); + // underlying std::string is not changed, only the view. + void remove_suffix(size_type n) { + assert(n <= length_); length_ -= n; } // string_view::swap() // // Swaps this `string_view` with another `string_view`. - ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR void swap(string_view& s) noexcept { + void swap(string_view& s) noexcept { auto t = *this; *this = s; s = t; @@ -394,21 +382,21 @@ class string_view { // Returns a "substring" of the `string_view` (at offset `pos` and length // `n`) as another string_view. This function throws `std::out_of_bounds` if // `pos > size`. - // Use absl::ClippedSubstr if you need a truncating substr operation. - constexpr string_view substr(size_type pos = 0, size_type n = npos) const { - return ABSL_PREDICT_FALSE(pos > length_) - ? (base_internal::ThrowStdOutOfRange( - "absl::string_view::substr"), - string_view()) - : string_view(ptr_ + pos, Min(n, length_ - pos)); + string_view substr(size_type pos, size_type n = npos) const { + if (ABSL_PREDICT_FALSE(pos > length_)) + base_internal::ThrowStdOutOfRange("absl::string_view::substr"); + n = (std::min)(n, length_ - pos); + return string_view(ptr_ + pos, n); } // string_view::compare() // - // Performs a lexicographical comparison between this `string_view` and - // another `string_view` `x`, returning a negative value if `*this` is less - // than `x`, 0 if `*this` is equal to `x`, and a positive value if `*this` - // is greater than `x`. + // Performs a lexicographical comparison between the `string_view` and + // another `absl::string_view`, returning -1 if `this` is less than, 0 if + // `this` is equal to, and 1 if `this` is greater than the passed std::string + // view. Note that in the case of data equality, a further comparison is made + // on the respective sizes of the two `string_view`s to determine which is + // smaller, equal, or greater. constexpr int compare(string_view x) const noexcept { return CompareImpl(length_, x.length_, Min(length_, x.length_) == 0 @@ -419,31 +407,31 @@ class string_view { // Overload of `string_view::compare()` for comparing a substring of the // 'string_view` and another `absl::string_view`. - constexpr int compare(size_type pos1, size_type count1, string_view v) const { + int compare(size_type pos1, size_type count1, string_view v) const { return substr(pos1, count1).compare(v); } // Overload of `string_view::compare()` for comparing a substring of the // `string_view` and a substring of another `absl::string_view`. - constexpr int compare(size_type pos1, size_type count1, string_view v, - size_type pos2, size_type count2) const { + int compare(size_type pos1, size_type count1, string_view v, size_type pos2, + size_type count2) const { return substr(pos1, count1).compare(v.substr(pos2, count2)); } // Overload of `string_view::compare()` for comparing a `string_view` and a - // a different C-style string `s`. - constexpr int compare(const char* s) const { return compare(string_view(s)); } + // a different C-style std::string `s`. + int compare(const char* s) const { return compare(string_view(s)); } // Overload of `string_view::compare()` for comparing a substring of the - // `string_view` and a different string C-style string `s`. - constexpr int compare(size_type pos1, size_type count1, const char* s) const { + // `string_view` and a different std::string C-style std::string `s`. + int compare(size_type pos1, size_type count1, const char* s) const { return substr(pos1, count1).compare(string_view(s)); } // Overload of `string_view::compare()` for comparing a substring of the - // `string_view` and a substring of a different C-style string `s`. - constexpr int compare(size_type pos1, size_type count1, const char* s, - size_type count2) const { + // `string_view` and a substring of a different C-style std::string `s`. + int compare(size_type pos1, size_type count1, const char* s, + size_type count2) const { return substr(pos1, count1).compare(string_view(s, count2)); } @@ -460,92 +448,48 @@ class string_view { // within the `string_view`. size_type find(char c, size_type pos = 0) const noexcept; - // Overload of `string_view::find()` for finding a substring of a different - // C-style string `s` within the `string_view`. - size_type find(const char* s, size_type pos, size_type count) const { - return find(string_view(s, count), pos); - } - - // Overload of `string_view::find()` for finding a different C-style string - // `s` within the `string_view`. - size_type find(const char* s, size_type pos = 0) const { - return find(string_view(s), pos); - } - // string_view::rfind() // // Finds the last occurrence of a substring `s` within the `string_view`, // returning the position of the first character's match, or `npos` if no // match was found. - size_type rfind(string_view s, size_type pos = npos) const noexcept; + size_type rfind(string_view s, size_type pos = npos) const + noexcept; // Overload of `string_view::rfind()` for finding the last given character `c` // within the `string_view`. size_type rfind(char c, size_type pos = npos) const noexcept; - // Overload of `string_view::rfind()` for finding a substring of a different - // C-style string `s` within the `string_view`. - size_type rfind(const char* s, size_type pos, size_type count) const { - return rfind(string_view(s, count), pos); - } - - // Overload of `string_view::rfind()` for finding a different C-style string - // `s` within the `string_view`. - size_type rfind(const char* s, size_type pos = npos) const { - return rfind(string_view(s), pos); - } - // string_view::find_first_of() // // Finds the first occurrence of any of the characters in `s` within the // `string_view`, returning the start position of the match, or `npos` if no // match was found. - size_type find_first_of(string_view s, size_type pos = 0) const noexcept; + size_type find_first_of(string_view s, size_type pos = 0) const + noexcept; // Overload of `string_view::find_first_of()` for finding a character `c` // within the `string_view`. - size_type find_first_of(char c, size_type pos = 0) const noexcept { + size_type find_first_of(char c, size_type pos = 0) const + noexcept { return find(c, pos); } - // Overload of `string_view::find_first_of()` for finding a substring of a - // different C-style string `s` within the `string_view`. - size_type find_first_of(const char* s, size_type pos, - size_type count) const { - return find_first_of(string_view(s, count), pos); - } - - // Overload of `string_view::find_first_of()` for finding a different C-style - // string `s` within the `string_view`. - size_type find_first_of(const char* s, size_type pos = 0) const { - return find_first_of(string_view(s), pos); - } - // string_view::find_last_of() // // Finds the last occurrence of any of the characters in `s` within the // `string_view`, returning the start position of the match, or `npos` if no // match was found. - size_type find_last_of(string_view s, size_type pos = npos) const noexcept; + size_type find_last_of(string_view s, size_type pos = npos) const + noexcept; // Overload of `string_view::find_last_of()` for finding a character `c` // within the `string_view`. - size_type find_last_of(char c, size_type pos = npos) const noexcept { + size_type find_last_of(char c, size_type pos = npos) const + noexcept { return rfind(c, pos); } - // Overload of `string_view::find_last_of()` for finding a substring of a - // different C-style string `s` within the `string_view`. - size_type find_last_of(const char* s, size_type pos, size_type count) const { - return find_last_of(string_view(s, count), pos); - } - - // Overload of `string_view::find_last_of()` for finding a different C-style - // string `s` within the `string_view`. - size_type find_last_of(const char* s, size_type pos = npos) const { - return find_last_of(string_view(s), pos); - } - // string_view::find_first_not_of() // // Finds the first occurrence of any of the characters not in `s` within the @@ -557,56 +501,25 @@ class string_view { // that is not `c` within the `string_view`. size_type find_first_not_of(char c, size_type pos = 0) const noexcept; - // Overload of `string_view::find_first_not_of()` for finding a substring of a - // different C-style string `s` within the `string_view`. - size_type find_first_not_of(const char* s, size_type pos, - size_type count) const { - return find_first_not_of(string_view(s, count), pos); - } - - // Overload of `string_view::find_first_not_of()` for finding a different - // C-style string `s` within the `string_view`. - size_type find_first_not_of(const char* s, size_type pos = 0) const { - return find_first_not_of(string_view(s), pos); - } - // string_view::find_last_not_of() // // Finds the last occurrence of any of the characters not in `s` within the // `string_view`, returning the start position of the last non-match, or // `npos` if no non-match was found. size_type find_last_not_of(string_view s, - size_type pos = npos) const noexcept; + size_type pos = npos) const noexcept; // Overload of `string_view::find_last_not_of()` for finding a character // that is not `c` within the `string_view`. - size_type find_last_not_of(char c, size_type pos = npos) const noexcept; - - // Overload of `string_view::find_last_not_of()` for finding a substring of a - // different C-style string `s` within the `string_view`. - size_type find_last_not_of(const char* s, size_type pos, - size_type count) const { - return find_last_not_of(string_view(s, count), pos); - } - - // Overload of `string_view::find_last_not_of()` for finding a different - // C-style string `s` within the `string_view`. - size_type find_last_not_of(const char* s, size_type pos = npos) const { - return find_last_not_of(string_view(s), pos); - } + size_type find_last_not_of(char c, size_type pos = npos) const + noexcept; private: - // The constructor from std::string delegates to this constructor. - // See the comment on that constructor for the rationale. - struct SkipCheckLengthTag {}; - string_view(const char* data, size_type len, SkipCheckLengthTag) noexcept - : ptr_(data), length_(len) {} - static constexpr size_type kMaxSize = (std::numeric_limits<difference_type>::max)(); static constexpr size_type CheckLengthInternal(size_type len) { - return ABSL_HARDENING_ASSERT(len <= kMaxSize), len; + return (void)ABSL_ASSERT(len <= kMaxSize), len; } static constexpr size_type StrlenInternal(const char* str) { @@ -677,7 +590,6 @@ std::ostream& operator<<(std::ostream& o, string_view piece); ABSL_NAMESPACE_END } // namespace absl -#undef ABSL_INTERNAL_STRING_VIEW_CXX14_CONSTEXPR #undef ABSL_INTERNAL_STRING_VIEW_MEMCMP #endif // ABSL_USES_STD_STRING_VIEW |