Abseil Common Libraries (C++) (grcp 依赖)
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406 lines
10 KiB
406 lines
10 KiB
// |
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// Copyright 2017 The Abseil Authors. |
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// |
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// Licensed under the Apache License, Version 2.0 (the "License"); |
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// you may not use this file except in compliance with the License. |
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// You may obtain a copy of the License at |
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// |
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// http://www.apache.org/licenses/LICENSE-2.0 |
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// |
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// Unless required by applicable law or agreed to in writing, software |
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// distributed under the License is distributed on an "AS IS" BASIS, |
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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// See the License for the specific language governing permissions and |
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// limitations under the License. |
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// |
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// |
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#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_ |
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#define ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_ |
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#include <limits.h> |
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#include <cstring> |
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#include <ostream> |
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#include "absl/base/port.h" |
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#include "absl/strings/internal/str_format/output.h" |
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#include "absl/strings/string_view.h" |
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class Cord; |
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namespace absl { |
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namespace str_format_internal { |
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class FormatRawSinkImpl { |
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public: |
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// Implicitly convert from any type that provides the hook function as |
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// described above. |
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template <typename T, decltype(str_format_internal::InvokeFlush( |
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std::declval<T*>(), string_view()))* = nullptr> |
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FormatRawSinkImpl(T* raw) // NOLINT |
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: sink_(raw), write_(&FormatRawSinkImpl::Flush<T>) {} |
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void Write(string_view s) { write_(sink_, s); } |
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template <typename T> |
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static FormatRawSinkImpl Extract(T s) { |
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return s.sink_; |
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} |
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private: |
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template <typename T> |
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static void Flush(void* r, string_view s) { |
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str_format_internal::InvokeFlush(static_cast<T*>(r), s); |
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} |
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void* sink_; |
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void (*write_)(void*, string_view); |
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}; |
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// An abstraction to which conversions write their string data. |
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class FormatSinkImpl { |
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public: |
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explicit FormatSinkImpl(FormatRawSinkImpl raw) : raw_(raw) {} |
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~FormatSinkImpl() { Flush(); } |
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void Flush() { |
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raw_.Write(string_view(buf_, pos_ - buf_)); |
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pos_ = buf_; |
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} |
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void Append(size_t n, char c) { |
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if (n == 0) return; |
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size_ += n; |
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auto raw_append = [&](size_t count) { |
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memset(pos_, c, count); |
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pos_ += count; |
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}; |
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while (n > Avail()) { |
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n -= Avail(); |
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if (Avail() > 0) { |
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raw_append(Avail()); |
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} |
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Flush(); |
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} |
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raw_append(n); |
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} |
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void Append(string_view v) { |
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size_t n = v.size(); |
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if (n == 0) return; |
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size_ += n; |
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if (n >= Avail()) { |
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Flush(); |
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raw_.Write(v); |
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return; |
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} |
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memcpy(pos_, v.data(), n); |
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pos_ += n; |
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} |
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size_t size() const { return size_; } |
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// Put 'v' to 'sink' with specified width, precision, and left flag. |
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bool PutPaddedString(string_view v, int w, int p, bool l); |
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template <typename T> |
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T Wrap() { |
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return T(this); |
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} |
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template <typename T> |
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static FormatSinkImpl* Extract(T* s) { |
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return s->sink_; |
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} |
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private: |
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size_t Avail() const { return buf_ + sizeof(buf_) - pos_; } |
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FormatRawSinkImpl raw_; |
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size_t size_ = 0; |
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char* pos_ = buf_; |
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char buf_[1024]; |
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}; |
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struct Flags { |
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bool basic : 1; // fastest conversion: no flags, width, or precision |
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bool left : 1; // "-" |
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bool show_pos : 1; // "+" |
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bool sign_col : 1; // " " |
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bool alt : 1; // "#" |
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bool zero : 1; // "0" |
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std::string ToString() const; |
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friend std::ostream& operator<<(std::ostream& os, const Flags& v) { |
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return os << v.ToString(); |
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} |
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}; |
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struct LengthMod { |
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public: |
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enum Id : uint8_t { |
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h, hh, l, ll, L, j, z, t, q, none |
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}; |
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static const size_t kNumValues = none + 1; |
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LengthMod() : id_(none) {} |
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// Index into the opaque array of LengthMod enums. |
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// Requires: i < kNumValues |
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static LengthMod FromIndex(size_t i) { |
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return LengthMod(kSpecs[i].value); |
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} |
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static LengthMod FromId(Id id) { return LengthMod(id); } |
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// The length modifier std::string associated with a specified LengthMod. |
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string_view name() const { |
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const Spec& spec = kSpecs[id_]; |
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return {spec.name, spec.name_length}; |
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} |
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Id id() const { return id_; } |
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friend bool operator==(const LengthMod& a, const LengthMod& b) { |
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return a.id() == b.id(); |
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} |
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friend bool operator!=(const LengthMod& a, const LengthMod& b) { |
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return !(a == b); |
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} |
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friend std::ostream& operator<<(std::ostream& os, const LengthMod& v) { |
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return os << v.name(); |
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} |
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private: |
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struct Spec { |
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Id value; |
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const char *name; |
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size_t name_length; |
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}; |
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static const Spec kSpecs[]; |
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explicit LengthMod(Id id) : id_(id) {} |
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Id id_; |
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}; |
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// clang-format off |
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#define ABSL_CONVERSION_CHARS_EXPAND_(X_VAL, X_SEP) \ |
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/* text */ \ |
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X_VAL(c) X_SEP X_VAL(C) X_SEP X_VAL(s) X_SEP X_VAL(S) X_SEP \ |
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/* ints */ \ |
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X_VAL(d) X_SEP X_VAL(i) X_SEP X_VAL(o) X_SEP \ |
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X_VAL(u) X_SEP X_VAL(x) X_SEP X_VAL(X) X_SEP \ |
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/* floats */ \ |
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X_VAL(f) X_SEP X_VAL(F) X_SEP X_VAL(e) X_SEP X_VAL(E) X_SEP \ |
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X_VAL(g) X_SEP X_VAL(G) X_SEP X_VAL(a) X_SEP X_VAL(A) X_SEP \ |
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/* misc */ \ |
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X_VAL(n) X_SEP X_VAL(p) |
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// clang-format on |
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struct ConversionChar { |
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public: |
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enum Id : uint8_t { |
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c, C, s, S, // text |
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d, i, o, u, x, X, // int |
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f, F, e, E, g, G, a, A, // float |
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n, p, // misc |
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none |
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}; |
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static const size_t kNumValues = none + 1; |
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ConversionChar() : id_(none) {} |
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public: |
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// Index into the opaque array of ConversionChar enums. |
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// Requires: i < kNumValues |
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static ConversionChar FromIndex(size_t i) { |
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return ConversionChar(kSpecs[i].value); |
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} |
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static ConversionChar FromChar(char c) { |
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ConversionChar::Id out_id = ConversionChar::none; |
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switch (c) { |
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#define X_VAL(id) \ |
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case #id[0]: \ |
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out_id = ConversionChar::id; \ |
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break; |
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ABSL_CONVERSION_CHARS_EXPAND_(X_VAL, ) |
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#undef X_VAL |
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default: |
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break; |
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} |
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return ConversionChar(out_id); |
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} |
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static ConversionChar FromId(Id id) { return ConversionChar(id); } |
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Id id() const { return id_; } |
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int radix() const { |
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switch (id()) { |
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case x: case X: case a: case A: case p: return 16; |
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case o: return 8; |
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default: return 10; |
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} |
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} |
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bool upper() const { |
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switch (id()) { |
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case X: case F: case E: case G: case A: return true; |
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default: return false; |
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} |
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} |
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bool is_signed() const { |
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switch (id()) { |
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case d: case i: return true; |
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default: return false; |
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} |
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} |
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bool is_integral() const { |
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switch (id()) { |
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case d: case i: case u: case o: case x: case X: |
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return true; |
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default: return false; |
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} |
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} |
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bool is_float() const { |
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switch (id()) { |
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case a: case e: case f: case g: case A: case E: case F: case G: |
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return true; |
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default: return false; |
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} |
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} |
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bool IsValid() const { return id() != none; } |
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// The associated char. |
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char Char() const { return kSpecs[id_].name; } |
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friend bool operator==(const ConversionChar& a, const ConversionChar& b) { |
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return a.id() == b.id(); |
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} |
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friend bool operator!=(const ConversionChar& a, const ConversionChar& b) { |
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return !(a == b); |
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} |
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friend std::ostream& operator<<(std::ostream& os, const ConversionChar& v) { |
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char c = v.Char(); |
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if (!c) c = '?'; |
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return os << c; |
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} |
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private: |
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struct Spec { |
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Id value; |
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char name; |
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}; |
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static const Spec kSpecs[]; |
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explicit ConversionChar(Id id) : id_(id) {} |
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Id id_; |
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}; |
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class ConversionSpec { |
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public: |
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Flags flags() const { return flags_; } |
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LengthMod length_mod() const { return length_mod_; } |
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ConversionChar conv() const { return conv_; } |
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// Returns the specified width. If width is unspecfied, it returns a negative |
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// value. |
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int width() const { return width_; } |
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// Returns the specified precision. If precision is unspecfied, it returns a |
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// negative value. |
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int precision() const { return precision_; } |
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void set_flags(Flags f) { flags_ = f; } |
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void set_length_mod(LengthMod lm) { length_mod_ = lm; } |
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void set_conv(ConversionChar c) { conv_ = c; } |
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void set_width(int w) { width_ = w; } |
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void set_precision(int p) { precision_ = p; } |
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void set_left(bool b) { flags_.left = b; } |
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private: |
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Flags flags_; |
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LengthMod length_mod_; |
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ConversionChar conv_; |
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int width_; |
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int precision_; |
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}; |
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constexpr uint64_t ConversionCharToConvValue(char conv) { |
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return |
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#define CONV_SET_CASE(c) \ |
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conv == #c[0] ? (uint64_t{1} << (1 + ConversionChar::Id::c)): |
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ABSL_CONVERSION_CHARS_EXPAND_(CONV_SET_CASE, ) |
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#undef CONV_SET_CASE |
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conv == '*' |
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? 1 |
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: 0; |
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} |
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enum class Conv : uint64_t { |
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#define CONV_SET_CASE(c) c = ConversionCharToConvValue(#c[0]), |
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ABSL_CONVERSION_CHARS_EXPAND_(CONV_SET_CASE, ) |
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#undef CONV_SET_CASE |
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// Used for width/precision '*' specification. |
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star = ConversionCharToConvValue('*'), |
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// Some predefined values: |
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integral = d | i | u | o | x | X, |
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floating = a | e | f | g | A | E | F | G, |
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numeric = integral | floating, |
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string = s, // absl:ignore(std::string) |
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pointer = p |
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}; |
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// Type safe OR operator. |
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// We need this for two reasons: |
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// 1. operator| on enums makes them decay to integers and the result is an |
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// integer. We need the result to stay as an enum. |
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// 2. We use "enum class" which would not work even if we accepted the decay. |
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constexpr Conv operator|(Conv a, Conv b) { |
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return Conv(static_cast<uint64_t>(a) | static_cast<uint64_t>(b)); |
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} |
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// Get a conversion with a single character in it. |
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constexpr Conv ConversionCharToConv(char c) { |
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return Conv(ConversionCharToConvValue(c)); |
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} |
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// Checks whether `c` exists in `set`. |
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constexpr bool Contains(Conv set, char c) { |
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return (static_cast<uint64_t>(set) & ConversionCharToConvValue(c)) != 0; |
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} |
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// Checks whether all the characters in `c` are contained in `set` |
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constexpr bool Contains(Conv set, Conv c) { |
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return (static_cast<uint64_t>(set) & static_cast<uint64_t>(c)) == |
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static_cast<uint64_t>(c); |
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} |
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// Return type of the AbslFormatConvert() functions. |
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// The Conv template parameter is used to inform the framework of what |
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// conversion characters are supported by that AbslFormatConvert routine. |
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template <Conv C> |
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struct ConvertResult { |
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static constexpr Conv kConv = C; |
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bool value; |
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}; |
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template <Conv C> |
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constexpr Conv ConvertResult<C>::kConv; |
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// Return capacity - used, clipped to a minimum of 0. |
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inline size_t Excess(size_t used, size_t capacity) { |
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return used < capacity ? capacity - used : 0; |
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} |
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} // namespace str_format_internal |
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} // namespace absl |
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#endif // ABSL_STRINGS_STR_FORMAT_EXTENSION_H_
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