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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/str_cat.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/strings/str_cat.h | 408 |
1 files changed, 0 insertions, 408 deletions
diff --git a/third_party/abseil_cpp/absl/strings/str_cat.h b/third_party/abseil_cpp/absl/strings/str_cat.h deleted file mode 100644 index a8a85c7322b2..000000000000 --- a/third_party/abseil_cpp/absl/strings/str_cat.h +++ /dev/null @@ -1,408 +0,0 @@ -// -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. -// -// ----------------------------------------------------------------------------- -// File: str_cat.h -// ----------------------------------------------------------------------------- -// -// This package contains functions for efficiently concatenating and appending -// strings: `StrCat()` and `StrAppend()`. Most of the work within these routines -// is actually handled through use of a special AlphaNum type, which was -// designed to be used as a parameter type that efficiently manages conversion -// to strings and avoids copies in the above operations. -// -// Any routine accepting either a string or a number may accept `AlphaNum`. -// The basic idea is that by accepting a `const AlphaNum &` as an argument -// to your function, your callers will automagically convert bools, integers, -// and floating point values to strings for you. -// -// NOTE: Use of `AlphaNum` outside of the //absl/strings package is unsupported -// except for the specific case of function parameters of type `AlphaNum` or -// `const AlphaNum &`. In particular, instantiating `AlphaNum` directly as a -// stack variable is not supported. -// -// Conversion from 8-bit values is not accepted because, if it were, then an -// attempt to pass ':' instead of ":" might result in a 58 ending up in your -// result. -// -// Bools convert to "0" or "1". Pointers to types other than `char *` are not -// valid inputs. No output is generated for null `char *` pointers. -// -// Floating point numbers are formatted with six-digit precision, which is -// the default for "std::cout <<" or printf "%g" (the same as "%.6g"). -// -// You can convert to hexadecimal output rather than decimal output using the -// `Hex` type contained here. To do so, pass `Hex(my_int)` as a parameter to -// `StrCat()` or `StrAppend()`. You may specify a minimum hex field width using -// a `PadSpec` enum. -// -// ----------------------------------------------------------------------------- - -#ifndef ABSL_STRINGS_STR_CAT_H_ -#define ABSL_STRINGS_STR_CAT_H_ - -#include <array> -#include <cstdint> -#include <string> -#include <type_traits> -#include <vector> - -#include "absl/base/port.h" -#include "absl/strings/numbers.h" -#include "absl/strings/string_view.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN - -namespace strings_internal { -// AlphaNumBuffer allows a way to pass a string to StrCat without having to do -// memory allocation. It is simply a pair of a fixed-size character array, and -// a size. Please don't use outside of absl, yet. -template <size_t max_size> -struct AlphaNumBuffer { - std::array<char, max_size> data; - size_t size; -}; - -} // namespace strings_internal - -// Enum that specifies the number of significant digits to return in a `Hex` or -// `Dec` conversion and fill character to use. A `kZeroPad2` value, for example, -// would produce hexadecimal strings such as "0a","0f" and a 'kSpacePad5' value -// would produce hexadecimal strings such as " a"," f". -enum PadSpec : uint8_t { - kNoPad = 1, - kZeroPad2, - kZeroPad3, - kZeroPad4, - kZeroPad5, - kZeroPad6, - kZeroPad7, - kZeroPad8, - kZeroPad9, - kZeroPad10, - kZeroPad11, - kZeroPad12, - kZeroPad13, - kZeroPad14, - kZeroPad15, - kZeroPad16, - kZeroPad17, - kZeroPad18, - kZeroPad19, - kZeroPad20, - - kSpacePad2 = kZeroPad2 + 64, - kSpacePad3, - kSpacePad4, - kSpacePad5, - kSpacePad6, - kSpacePad7, - kSpacePad8, - kSpacePad9, - kSpacePad10, - kSpacePad11, - kSpacePad12, - kSpacePad13, - kSpacePad14, - kSpacePad15, - kSpacePad16, - kSpacePad17, - kSpacePad18, - kSpacePad19, - kSpacePad20, -}; - -// ----------------------------------------------------------------------------- -// Hex -// ----------------------------------------------------------------------------- -// -// `Hex` stores a set of hexadecimal string conversion parameters for use -// within `AlphaNum` string conversions. -struct Hex { - uint64_t value; - uint8_t width; - char fill; - - template <typename Int> - explicit Hex( - Int v, PadSpec spec = absl::kNoPad, - typename std::enable_if<sizeof(Int) == 1 && - !std::is_pointer<Int>::value>::type* = nullptr) - : Hex(spec, static_cast<uint8_t>(v)) {} - template <typename Int> - explicit Hex( - Int v, PadSpec spec = absl::kNoPad, - typename std::enable_if<sizeof(Int) == 2 && - !std::is_pointer<Int>::value>::type* = nullptr) - : Hex(spec, static_cast<uint16_t>(v)) {} - template <typename Int> - explicit Hex( - Int v, PadSpec spec = absl::kNoPad, - typename std::enable_if<sizeof(Int) == 4 && - !std::is_pointer<Int>::value>::type* = nullptr) - : Hex(spec, static_cast<uint32_t>(v)) {} - template <typename Int> - explicit Hex( - Int v, PadSpec spec = absl::kNoPad, - typename std::enable_if<sizeof(Int) == 8 && - !std::is_pointer<Int>::value>::type* = nullptr) - : Hex(spec, static_cast<uint64_t>(v)) {} - template <typename Pointee> - explicit Hex(Pointee* v, PadSpec spec = absl::kNoPad) - : Hex(spec, reinterpret_cast<uintptr_t>(v)) {} - - private: - Hex(PadSpec spec, uint64_t v) - : value(v), - width(spec == absl::kNoPad - ? 1 - : spec >= absl::kSpacePad2 ? spec - absl::kSpacePad2 + 2 - : spec - absl::kZeroPad2 + 2), - fill(spec >= absl::kSpacePad2 ? ' ' : '0') {} -}; - -// ----------------------------------------------------------------------------- -// Dec -// ----------------------------------------------------------------------------- -// -// `Dec` stores a set of decimal string conversion parameters for use -// within `AlphaNum` string conversions. Dec is slower than the default -// integer conversion, so use it only if you need padding. -struct Dec { - uint64_t value; - uint8_t width; - char fill; - bool neg; - - template <typename Int> - explicit Dec(Int v, PadSpec spec = absl::kNoPad, - typename std::enable_if<(sizeof(Int) <= 8)>::type* = nullptr) - : value(v >= 0 ? static_cast<uint64_t>(v) - : uint64_t{0} - static_cast<uint64_t>(v)), - width(spec == absl::kNoPad - ? 1 - : spec >= absl::kSpacePad2 ? spec - absl::kSpacePad2 + 2 - : spec - absl::kZeroPad2 + 2), - fill(spec >= absl::kSpacePad2 ? ' ' : '0'), - neg(v < 0) {} -}; - -// ----------------------------------------------------------------------------- -// AlphaNum -// ----------------------------------------------------------------------------- -// -// The `AlphaNum` class acts as the main parameter type for `StrCat()` and -// `StrAppend()`, providing efficient conversion of numeric, boolean, and -// hexadecimal values (through the `Hex` type) into strings. - -class AlphaNum { - public: - // No bool ctor -- bools convert to an integral type. - // A bool ctor would also convert incoming pointers (bletch). - - AlphaNum(int x) // NOLINT(runtime/explicit) - : piece_(digits_, - numbers_internal::FastIntToBuffer(x, digits_) - &digits_[0]) {} - AlphaNum(unsigned int x) // NOLINT(runtime/explicit) - : piece_(digits_, - numbers_internal::FastIntToBuffer(x, digits_) - &digits_[0]) {} - AlphaNum(long x) // NOLINT(*) - : piece_(digits_, - numbers_internal::FastIntToBuffer(x, digits_) - &digits_[0]) {} - AlphaNum(unsigned long x) // NOLINT(*) - : piece_(digits_, - numbers_internal::FastIntToBuffer(x, digits_) - &digits_[0]) {} - AlphaNum(long long x) // NOLINT(*) - : piece_(digits_, - numbers_internal::FastIntToBuffer(x, digits_) - &digits_[0]) {} - AlphaNum(unsigned long long x) // NOLINT(*) - : piece_(digits_, - numbers_internal::FastIntToBuffer(x, digits_) - &digits_[0]) {} - - AlphaNum(float f) // NOLINT(runtime/explicit) - : piece_(digits_, numbers_internal::SixDigitsToBuffer(f, digits_)) {} - AlphaNum(double f) // NOLINT(runtime/explicit) - : piece_(digits_, numbers_internal::SixDigitsToBuffer(f, digits_)) {} - - AlphaNum(Hex hex); // NOLINT(runtime/explicit) - AlphaNum(Dec dec); // NOLINT(runtime/explicit) - - template <size_t size> - AlphaNum( // NOLINT(runtime/explicit) - const strings_internal::AlphaNumBuffer<size>& buf) - : piece_(&buf.data[0], buf.size) {} - - AlphaNum(const char* c_str) : piece_(c_str) {} // NOLINT(runtime/explicit) - AlphaNum(absl::string_view pc) : piece_(pc) {} // NOLINT(runtime/explicit) - - template <typename Allocator> - AlphaNum( // NOLINT(runtime/explicit) - const std::basic_string<char, std::char_traits<char>, Allocator>& str) - : piece_(str) {} - - // Use string literals ":" instead of character literals ':'. - AlphaNum(char c) = delete; // NOLINT(runtime/explicit) - - AlphaNum(const AlphaNum&) = delete; - AlphaNum& operator=(const AlphaNum&) = delete; - - absl::string_view::size_type size() const { return piece_.size(); } - const char* data() const { return piece_.data(); } - absl::string_view Piece() const { return piece_; } - - // Normal enums are already handled by the integer formatters. - // This overload matches only scoped enums. - template <typename T, - typename = typename std::enable_if< - std::is_enum<T>{} && !std::is_convertible<T, int>{}>::type> - AlphaNum(T e) // NOLINT(runtime/explicit) - : AlphaNum(static_cast<typename std::underlying_type<T>::type>(e)) {} - - // vector<bool>::reference and const_reference require special help to - // convert to `AlphaNum` because it requires two user defined conversions. - template < - typename T, - typename std::enable_if< - std::is_class<T>::value && - (std::is_same<T, std::vector<bool>::reference>::value || - std::is_same<T, std::vector<bool>::const_reference>::value)>::type* = - nullptr> - AlphaNum(T e) : AlphaNum(static_cast<bool>(e)) {} // NOLINT(runtime/explicit) - - private: - absl::string_view piece_; - char digits_[numbers_internal::kFastToBufferSize]; -}; - -// ----------------------------------------------------------------------------- -// StrCat() -// ----------------------------------------------------------------------------- -// -// Merges given strings or numbers, using no delimiter(s), returning the merged -// result as a string. -// -// `StrCat()` is designed to be the fastest possible way to construct a string -// out of a mix of raw C strings, string_views, strings, bool values, -// and numeric values. -// -// Don't use `StrCat()` for user-visible strings. The localization process -// works poorly on strings built up out of fragments. -// -// For clarity and performance, don't use `StrCat()` when appending to a -// string. Use `StrAppend()` instead. In particular, avoid using any of these -// (anti-)patterns: -// -// str.append(StrCat(...)) -// str += StrCat(...) -// str = StrCat(str, ...) -// -// The last case is the worst, with a potential to change a loop -// from a linear time operation with O(1) dynamic allocations into a -// quadratic time operation with O(n) dynamic allocations. -// -// See `StrAppend()` below for more information. - -namespace strings_internal { - -// Do not call directly - this is not part of the public API. -std::string CatPieces(std::initializer_list<absl::string_view> pieces); -void AppendPieces(std::string* dest, - std::initializer_list<absl::string_view> pieces); - -} // namespace strings_internal - -ABSL_MUST_USE_RESULT inline std::string StrCat() { return std::string(); } - -ABSL_MUST_USE_RESULT inline std::string StrCat(const AlphaNum& a) { - return std::string(a.data(), a.size()); -} - -ABSL_MUST_USE_RESULT std::string StrCat(const AlphaNum& a, const AlphaNum& b); -ABSL_MUST_USE_RESULT std::string StrCat(const AlphaNum& a, const AlphaNum& b, - const AlphaNum& c); -ABSL_MUST_USE_RESULT std::string StrCat(const AlphaNum& a, const AlphaNum& b, - const AlphaNum& c, const AlphaNum& d); - -// Support 5 or more arguments -template <typename... AV> -ABSL_MUST_USE_RESULT inline std::string StrCat( - const AlphaNum& a, const AlphaNum& b, const AlphaNum& c, const AlphaNum& d, - const AlphaNum& e, const AV&... args) { - return strings_internal::CatPieces( - {a.Piece(), b.Piece(), c.Piece(), d.Piece(), e.Piece(), - static_cast<const AlphaNum&>(args).Piece()...}); -} - -// ----------------------------------------------------------------------------- -// StrAppend() -// ----------------------------------------------------------------------------- -// -// Appends a string or set of strings to an existing string, in a similar -// fashion to `StrCat()`. -// -// WARNING: `StrAppend(&str, a, b, c, ...)` requires that none of the -// a, b, c, parameters be a reference into str. For speed, `StrAppend()` does -// not try to check each of its input arguments to be sure that they are not -// a subset of the string being appended to. That is, while this will work: -// -// std::string s = "foo"; -// s += s; -// -// This output is undefined: -// -// std::string s = "foo"; -// StrAppend(&s, s); -// -// This output is undefined as well, since `absl::string_view` does not own its -// data: -// -// std::string s = "foobar"; -// absl::string_view p = s; -// StrAppend(&s, p); - -inline void StrAppend(std::string*) {} -void StrAppend(std::string* dest, const AlphaNum& a); -void StrAppend(std::string* dest, const AlphaNum& a, const AlphaNum& b); -void StrAppend(std::string* dest, const AlphaNum& a, const AlphaNum& b, - const AlphaNum& c); -void StrAppend(std::string* dest, const AlphaNum& a, const AlphaNum& b, - const AlphaNum& c, const AlphaNum& d); - -// Support 5 or more arguments -template <typename... AV> -inline void StrAppend(std::string* dest, const AlphaNum& a, const AlphaNum& b, - const AlphaNum& c, const AlphaNum& d, const AlphaNum& e, - const AV&... args) { - strings_internal::AppendPieces( - dest, {a.Piece(), b.Piece(), c.Piece(), d.Piece(), e.Piece(), - static_cast<const AlphaNum&>(args).Piece()...}); -} - -// Helper function for the future StrCat default floating-point format, %.6g -// This is fast. -inline strings_internal::AlphaNumBuffer< - numbers_internal::kSixDigitsToBufferSize> -SixDigits(double d) { - strings_internal::AlphaNumBuffer<numbers_internal::kSixDigitsToBufferSize> - result; - result.size = numbers_internal::SixDigitsToBuffer(d, &result.data[0]); - return result; -} - -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_STRINGS_STR_CAT_H_ |