ecency-mobile/ios/Pods/Folly/folly/Format-inl.h

1099 lines
32 KiB
C++

/*
* Copyright 2016 Facebook, Inc.
*
* 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
*
* http://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.
*/
#ifndef FOLLY_FORMAT_H_
#error This file may only be included from Format.h.
#endif
#include <array>
#include <cinttypes>
#include <deque>
#include <map>
#include <unordered_map>
#include <vector>
#include <folly/Exception.h>
#include <folly/FormatTraits.h>
#include <folly/Traits.h>
#include <folly/portability/Windows.h>
// Ignore -Wformat-nonliteral warnings within this file
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
namespace folly {
namespace detail {
// Updates the end of the buffer after the comma separators have been added.
void insertThousandsGroupingUnsafe(char* start_buffer, char** end_buffer);
extern const char formatHexUpper[256][2];
extern const char formatHexLower[256][2];
extern const char formatOctal[512][3];
extern const char formatBinary[256][8];
const size_t kMaxHexLength = 2 * sizeof(uintmax_t);
const size_t kMaxOctalLength = 3 * sizeof(uintmax_t);
const size_t kMaxBinaryLength = 8 * sizeof(uintmax_t);
/**
* Convert an unsigned to hex, using repr (which maps from each possible
* 2-hex-bytes value to the 2-character representation).
*
* Just like folly::detail::uintToBuffer in Conv.h, writes at the *end* of
* the supplied buffer and returns the offset of the beginning of the string
* from the start of the buffer. The formatted string will be in range
* [buf+begin, buf+bufLen).
*/
template <class Uint>
size_t uintToHex(char* buffer, size_t bufLen, Uint v,
const char (&repr)[256][2]) {
// 'v >>= 7, v >>= 1' is no more than a work around to get rid of shift size
// warning when Uint = uint8_t (it's false as v >= 256 implies sizeof(v) > 1).
for (; !less_than<unsigned, 256>(v); v >>= 7, v >>= 1) {
auto b = v & 0xff;
bufLen -= 2;
buffer[bufLen] = repr[b][0];
buffer[bufLen + 1] = repr[b][1];
}
buffer[--bufLen] = repr[v][1];
if (v >= 16) {
buffer[--bufLen] = repr[v][0];
}
return bufLen;
}
/**
* Convert an unsigned to hex, using lower-case letters for the digits
* above 9. See the comments for uintToHex.
*/
template <class Uint>
inline size_t uintToHexLower(char* buffer, size_t bufLen, Uint v) {
return uintToHex(buffer, bufLen, v, formatHexLower);
}
/**
* Convert an unsigned to hex, using upper-case letters for the digits
* above 9. See the comments for uintToHex.
*/
template <class Uint>
inline size_t uintToHexUpper(char* buffer, size_t bufLen, Uint v) {
return uintToHex(buffer, bufLen, v, formatHexUpper);
}
/**
* Convert an unsigned to octal.
*
* Just like folly::detail::uintToBuffer in Conv.h, writes at the *end* of
* the supplied buffer and returns the offset of the beginning of the string
* from the start of the buffer. The formatted string will be in range
* [buf+begin, buf+bufLen).
*/
template <class Uint>
size_t uintToOctal(char* buffer, size_t bufLen, Uint v) {
auto& repr = formatOctal;
// 'v >>= 7, v >>= 2' is no more than a work around to get rid of shift size
// warning when Uint = uint8_t (it's false as v >= 512 implies sizeof(v) > 1).
for (; !less_than<unsigned, 512>(v); v >>= 7, v >>= 2) {
auto b = v & 0x1ff;
bufLen -= 3;
buffer[bufLen] = repr[b][0];
buffer[bufLen + 1] = repr[b][1];
buffer[bufLen + 2] = repr[b][2];
}
buffer[--bufLen] = repr[v][2];
if (v >= 8) {
buffer[--bufLen] = repr[v][1];
}
if (v >= 64) {
buffer[--bufLen] = repr[v][0];
}
return bufLen;
}
/**
* Convert an unsigned to binary.
*
* Just like folly::detail::uintToBuffer in Conv.h, writes at the *end* of
* the supplied buffer and returns the offset of the beginning of the string
* from the start of the buffer. The formatted string will be in range
* [buf+begin, buf+bufLen).
*/
template <class Uint>
size_t uintToBinary(char* buffer, size_t bufLen, Uint v) {
auto& repr = formatBinary;
if (v == 0) {
buffer[--bufLen] = '0';
return bufLen;
}
for (; v; v >>= 7, v >>= 1) {
auto b = v & 0xff;
bufLen -= 8;
memcpy(buffer + bufLen, &(repr[b][0]), 8);
}
while (buffer[bufLen] == '0') {
++bufLen;
}
return bufLen;
}
} // namespace detail
template <class Derived, bool containerMode, class... Args>
BaseFormatter<Derived, containerMode, Args...>::BaseFormatter(StringPiece str,
Args&&... args)
: str_(str),
values_(FormatValue<typename std::decay<Args>::type>(
std::forward<Args>(args))...) {
static_assert(!containerMode || sizeof...(Args) == 1,
"Exactly one argument required in container mode");
}
template <class Derived, bool containerMode, class... Args>
template <class Output>
void BaseFormatter<Derived, containerMode, Args...>::operator()(Output& out)
const {
// Copy raw string (without format specifiers) to output;
// not as simple as we'd like, as we still need to translate "}}" to "}"
// and throw if we see any lone "}"
auto outputString = [&out] (StringPiece s) {
auto p = s.begin();
auto end = s.end();
while (p != end) {
auto q = static_cast<const char*>(memchr(p, '}', end - p));
if (!q) {
out(StringPiece(p, end));
break;
}
++q;
out(StringPiece(p, q));
p = q;
if (p == end || *p != '}') {
throw BadFormatArg("folly::format: single '}' in format string");
}
++p;
}
};
auto p = str_.begin();
auto end = str_.end();
int nextArg = 0;
bool hasDefaultArgIndex = false;
bool hasExplicitArgIndex = false;
while (p != end) {
auto q = static_cast<const char*>(memchr(p, '{', end - p));
if (!q) {
outputString(StringPiece(p, end));
break;
}
outputString(StringPiece(p, q));
p = q + 1;
if (p == end) {
throw BadFormatArg("folly::format: '}' at end of format string");
}
// "{{" -> "{"
if (*p == '{') {
out(StringPiece(p, 1));
++p;
continue;
}
// Format string
q = static_cast<const char*>(memchr(p, '}', end - p));
if (q == nullptr) {
throw BadFormatArg("folly::format: missing ending '}'");
}
FormatArg arg(StringPiece(p, q));
p = q + 1;
int argIndex = 0;
auto piece = arg.splitKey<true>(); // empty key component is okay
if (containerMode) { // static
arg.enforce(arg.width != FormatArg::kDynamicWidth,
"dynamic field width not supported in vformat()");
if (piece.empty()) {
arg.setNextIntKey(nextArg++);
hasDefaultArgIndex = true;
} else {
arg.setNextKey(piece);
hasExplicitArgIndex = true;
}
} else {
if (piece.empty()) {
if (arg.width == FormatArg::kDynamicWidth) {
arg.enforce(arg.widthIndex == FormatArg::kNoIndex,
"cannot provide width arg index without value arg index");
int sizeArg = nextArg++;
arg.width = getSizeArg(sizeArg, arg);
}
argIndex = nextArg++;
hasDefaultArgIndex = true;
} else {
if (arg.width == FormatArg::kDynamicWidth) {
arg.enforce(arg.widthIndex != FormatArg::kNoIndex,
"cannot provide value arg index without width arg index");
arg.width = getSizeArg(arg.widthIndex, arg);
}
try {
argIndex = to<int>(piece);
} catch (const std::out_of_range& e) {
arg.error("argument index must be integer");
}
arg.enforce(argIndex >= 0, "argument index must be non-negative");
hasExplicitArgIndex = true;
}
}
if (hasDefaultArgIndex && hasExplicitArgIndex) {
throw BadFormatArg(
"folly::format: may not have both default and explicit arg indexes");
}
doFormat(argIndex, arg, out);
}
}
template <class Derived, bool containerMode, class... Args>
void writeTo(FILE* fp,
const BaseFormatter<Derived, containerMode, Args...>& formatter) {
auto writer = [fp] (StringPiece sp) {
size_t n = fwrite(sp.data(), 1, sp.size(), fp);
if (n < sp.size()) {
throwSystemError("Formatter writeTo", "fwrite failed");
}
};
formatter(writer);
}
namespace format_value {
template <class FormatCallback>
void formatString(StringPiece val, FormatArg& arg, FormatCallback& cb) {
if (arg.width != FormatArg::kDefaultWidth && arg.width < 0) {
throw BadFormatArg("folly::format: invalid width");
}
if (arg.precision != FormatArg::kDefaultPrecision && arg.precision < 0) {
throw BadFormatArg("folly::format: invalid precision");
}
// XXX: clang should be smart enough to not need the two static_cast<size_t>
// uses below given the above checks. If clang ever becomes that smart, we
// should remove the otherwise unnecessary warts.
if (arg.precision != FormatArg::kDefaultPrecision &&
val.size() > static_cast<size_t>(arg.precision)) {
val.reset(val.data(), arg.precision);
}
constexpr int padBufSize = 128;
char padBuf[padBufSize];
// Output padding, no more than padBufSize at once
auto pad = [&padBuf, &cb, padBufSize] (int chars) {
while (chars) {
int n = std::min(chars, padBufSize);
cb(StringPiece(padBuf, n));
chars -= n;
}
};
int padRemaining = 0;
if (arg.width != FormatArg::kDefaultWidth &&
val.size() < static_cast<size_t>(arg.width)) {
char fill = arg.fill == FormatArg::kDefaultFill ? ' ' : arg.fill;
int padChars = static_cast<int> (arg.width - val.size());
memset(padBuf, fill, std::min(padBufSize, padChars));
switch (arg.align) {
case FormatArg::Align::DEFAULT:
case FormatArg::Align::LEFT:
padRemaining = padChars;
break;
case FormatArg::Align::CENTER:
pad(padChars / 2);
padRemaining = padChars - padChars / 2;
break;
case FormatArg::Align::RIGHT:
case FormatArg::Align::PAD_AFTER_SIGN:
pad(padChars);
break;
default:
abort();
break;
}
}
cb(val);
if (padRemaining) {
pad(padRemaining);
}
}
template <class FormatCallback>
void formatNumber(StringPiece val, int prefixLen, FormatArg& arg,
FormatCallback& cb) {
// precision means something different for numbers
arg.precision = FormatArg::kDefaultPrecision;
if (arg.align == FormatArg::Align::DEFAULT) {
arg.align = FormatArg::Align::RIGHT;
} else if (prefixLen && arg.align == FormatArg::Align::PAD_AFTER_SIGN) {
// Split off the prefix, then do any padding if necessary
cb(val.subpiece(0, prefixLen));
val.advance(prefixLen);
arg.width = std::max(arg.width - prefixLen, 0);
}
format_value::formatString(val, arg, cb);
}
template <class FormatCallback,
class Derived,
bool containerMode,
class... Args>
void formatFormatter(
const BaseFormatter<Derived, containerMode, Args...>& formatter,
FormatArg& arg,
FormatCallback& cb) {
if (arg.width == FormatArg::kDefaultWidth &&
arg.precision == FormatArg::kDefaultPrecision) {
// nothing to do
formatter(cb);
} else if (arg.align != FormatArg::Align::LEFT &&
arg.align != FormatArg::Align::DEFAULT) {
// We can only avoid creating a temporary string if we align left,
// as we'd need to know the size beforehand otherwise
format_value::formatString(formatter.fbstr(), arg, cb);
} else {
auto fn = [&arg, &cb] (StringPiece sp) mutable {
int sz = static_cast<int>(sp.size());
if (arg.precision != FormatArg::kDefaultPrecision) {
sz = std::min(arg.precision, sz);
sp.reset(sp.data(), sz);
arg.precision -= sz;
}
if (!sp.empty()) {
cb(sp);
if (arg.width != FormatArg::kDefaultWidth) {
arg.width = std::max(arg.width - sz, 0);
}
}
};
formatter(fn);
if (arg.width != FormatArg::kDefaultWidth && arg.width != 0) {
// Rely on formatString to do appropriate padding
format_value::formatString(StringPiece(), arg, cb);
}
}
}
} // namespace format_value
// Definitions for default FormatValue classes
// Integral types (except bool)
template <class T>
class FormatValue<
T, typename std::enable_if<
std::is_integral<T>::value &&
!std::is_same<T, bool>::value>::type>
{
public:
explicit FormatValue(T val) : val_(val) { }
T getValue() const {
return val_;
}
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
arg.validate(FormatArg::Type::INTEGER);
doFormat(arg, cb);
}
template <class FormatCallback>
void doFormat(FormatArg& arg, FormatCallback& cb) const {
char presentation = arg.presentation;
if (presentation == FormatArg::kDefaultPresentation) {
presentation = std::is_same<T, char>::value ? 'c' : 'd';
}
// Do all work as unsigned, we'll add the prefix ('0' or '0x' if necessary)
// and sign ourselves.
typedef typename std::make_unsigned<T>::type UT;
UT uval;
char sign;
if (std::is_signed<T>::value) {
if (folly::is_negative(val_)) {
uval = -static_cast<UT>(val_);
sign = '-';
} else {
uval = static_cast<UT>(val_);
switch (arg.sign) {
case FormatArg::Sign::PLUS_OR_MINUS:
sign = '+';
break;
case FormatArg::Sign::SPACE_OR_MINUS:
sign = ' ';
break;
default:
sign = '\0';
break;
}
}
} else {
uval = val_;
sign = '\0';
arg.enforce(arg.sign == FormatArg::Sign::DEFAULT,
"sign specifications not allowed for unsigned values");
}
// max of:
// #x: 0x prefix + 16 bytes = 18 bytes
// #o: 0 prefix + 22 bytes = 23 bytes
// #b: 0b prefix + 64 bytes = 65 bytes
// ,d: 26 bytes (including thousands separators!)
// + nul terminator
// + 3 for sign and prefix shenanigans (see below)
constexpr size_t valBufSize = 69;
char valBuf[valBufSize];
char* valBufBegin = nullptr;
char* valBufEnd = nullptr;
int prefixLen = 0;
switch (presentation) {
case 'n': {
arg.enforce(!arg.basePrefix,
"base prefix not allowed with '", presentation,
"' specifier");
arg.enforce(!arg.thousandsSeparator,
"cannot use ',' with the '", presentation,
"' specifier");
valBufBegin = valBuf + 3; // room for sign and base prefix
#if defined(__ANDROID__)
int len = snprintf(valBufBegin, (valBuf + valBufSize) - valBufBegin,
"%" PRIuMAX, static_cast<uintmax_t>(uval));
#else
int len = snprintf(valBufBegin, (valBuf + valBufSize) - valBufBegin,
"%ju", static_cast<uintmax_t>(uval));
#endif
// valBufSize should always be big enough, so this should never
// happen.
assert(len < valBuf + valBufSize - valBufBegin);
valBufEnd = valBufBegin + len;
break;
}
case 'd':
arg.enforce(!arg.basePrefix,
"base prefix not allowed with '", presentation,
"' specifier");
valBufBegin = valBuf + 3; // room for sign and base prefix
// Use uintToBuffer, faster than sprintf
valBufEnd = valBufBegin + uint64ToBufferUnsafe(uval, valBufBegin);
if (arg.thousandsSeparator) {
detail::insertThousandsGroupingUnsafe(valBufBegin, &valBufEnd);
}
break;
case 'c':
arg.enforce(!arg.basePrefix,
"base prefix not allowed with '", presentation,
"' specifier");
arg.enforce(!arg.thousandsSeparator,
"thousands separator (',') not allowed with '",
presentation, "' specifier");
valBufBegin = valBuf + 3;
*valBufBegin = static_cast<char>(uval);
valBufEnd = valBufBegin + 1;
break;
case 'o':
case 'O':
arg.enforce(!arg.thousandsSeparator,
"thousands separator (',') not allowed with '",
presentation, "' specifier");
valBufEnd = valBuf + valBufSize - 1;
valBufBegin = valBuf + detail::uintToOctal(valBuf, valBufSize - 1, uval);
if (arg.basePrefix) {
*--valBufBegin = '0';
prefixLen = 1;
}
break;
case 'x':
arg.enforce(!arg.thousandsSeparator,
"thousands separator (',') not allowed with '",
presentation, "' specifier");
valBufEnd = valBuf + valBufSize - 1;
valBufBegin = valBuf + detail::uintToHexLower(valBuf, valBufSize - 1,
uval);
if (arg.basePrefix) {
*--valBufBegin = 'x';
*--valBufBegin = '0';
prefixLen = 2;
}
break;
case 'X':
arg.enforce(!arg.thousandsSeparator,
"thousands separator (',') not allowed with '",
presentation, "' specifier");
valBufEnd = valBuf + valBufSize - 1;
valBufBegin = valBuf + detail::uintToHexUpper(valBuf, valBufSize - 1,
uval);
if (arg.basePrefix) {
*--valBufBegin = 'X';
*--valBufBegin = '0';
prefixLen = 2;
}
break;
case 'b':
case 'B':
arg.enforce(!arg.thousandsSeparator,
"thousands separator (',') not allowed with '",
presentation, "' specifier");
valBufEnd = valBuf + valBufSize - 1;
valBufBegin = valBuf + detail::uintToBinary(valBuf, valBufSize - 1,
uval);
if (arg.basePrefix) {
*--valBufBegin = presentation; // 0b or 0B
*--valBufBegin = '0';
prefixLen = 2;
}
break;
default:
arg.error("invalid specifier '", presentation, "'");
}
if (sign) {
*--valBufBegin = sign;
++prefixLen;
}
format_value::formatNumber(StringPiece(valBufBegin, valBufEnd), prefixLen,
arg, cb);
}
private:
T val_;
};
// Bool
template <>
class FormatValue<bool> {
public:
explicit FormatValue(bool val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
if (arg.presentation == FormatArg::kDefaultPresentation) {
arg.validate(FormatArg::Type::OTHER);
format_value::formatString(val_ ? "true" : "false", arg, cb);
} else { // number
FormatValue<int>(val_).format(arg, cb);
}
}
private:
bool val_;
};
// double
template <>
class FormatValue<double> {
public:
explicit FormatValue(double val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
fbstring piece;
int prefixLen;
formatHelper(piece, prefixLen, arg);
format_value::formatNumber(piece, prefixLen, arg, cb);
}
private:
void formatHelper(fbstring& piece, int& prefixLen, FormatArg& arg) const;
double val_;
};
// float (defer to double)
template <>
class FormatValue<float> {
public:
explicit FormatValue(float val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
FormatValue<double>(val_).format(arg, cb);
}
private:
float val_;
};
// Sring-y types (implicitly convertible to StringPiece, except char*)
template <class T>
class FormatValue<
T, typename std::enable_if<
(!std::is_pointer<T>::value ||
!std::is_same<char, typename std::decay<
typename std::remove_pointer<T>::type>::type>::value) &&
std::is_convertible<T, StringPiece>::value>::type>
{
public:
explicit FormatValue(StringPiece val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
if (arg.keyEmpty()) {
arg.validate(FormatArg::Type::OTHER);
arg.enforce(arg.presentation == FormatArg::kDefaultPresentation ||
arg.presentation == 's',
"invalid specifier '", arg.presentation, "'");
format_value::formatString(val_, arg, cb);
} else {
FormatValue<char>(val_.at(arg.splitIntKey())).format(arg, cb);
}
}
private:
StringPiece val_;
};
// Null
template <>
class FormatValue<std::nullptr_t> {
public:
explicit FormatValue(std::nullptr_t) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
arg.validate(FormatArg::Type::OTHER);
arg.enforce(arg.presentation == FormatArg::kDefaultPresentation,
"invalid specifier '", arg.presentation, "'");
format_value::formatString("(null)", arg, cb);
}
};
// Partial specialization of FormatValue for char*
template <class T>
class FormatValue<
T*,
typename std::enable_if<
std::is_same<char, typename std::decay<T>::type>::value>::type>
{
public:
explicit FormatValue(T* val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
if (arg.keyEmpty()) {
if (!val_) {
FormatValue<std::nullptr_t>(nullptr).format(arg, cb);
} else {
FormatValue<StringPiece>(val_).format(arg, cb);
}
} else {
FormatValue<typename std::decay<T>::type>(
val_[arg.splitIntKey()]).format(arg, cb);
}
}
private:
T* val_;
};
// Partial specialization of FormatValue for void*
template <class T>
class FormatValue<
T*,
typename std::enable_if<
std::is_same<void, typename std::decay<T>::type>::value>::type>
{
public:
explicit FormatValue(T* val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
if (!val_) {
FormatValue<std::nullptr_t>(nullptr).format(arg, cb);
} else {
// Print as a pointer, in hex.
arg.validate(FormatArg::Type::OTHER);
arg.enforce(arg.presentation == FormatArg::kDefaultPresentation,
"invalid specifier '", arg.presentation, "'");
arg.basePrefix = true;
arg.presentation = 'x';
if (arg.align == FormatArg::Align::DEFAULT) {
arg.align = FormatArg::Align::LEFT;
}
FormatValue<uintptr_t>(
reinterpret_cast<uintptr_t>(val_)).doFormat(arg, cb);
}
}
private:
T* val_;
};
template <class T, class = void>
class TryFormatValue {
public:
template <class FormatCallback>
static void formatOrFail(T& /* value */,
FormatArg& arg,
FormatCallback& /* cb */) {
arg.error("No formatter available for this type");
}
};
template <class T>
class TryFormatValue<
T,
typename std::enable_if<
0 < sizeof(FormatValue<typename std::decay<T>::type>)>::type>
{
public:
template <class FormatCallback>
static void formatOrFail(T& value, FormatArg& arg, FormatCallback& cb) {
FormatValue<typename std::decay<T>::type>(value).format(arg, cb);
}
};
// Partial specialization of FormatValue for other pointers
template <class T>
class FormatValue<
T*,
typename std::enable_if<
!std::is_same<char, typename std::decay<T>::type>::value &&
!std::is_same<void, typename std::decay<T>::type>::value>::type>
{
public:
explicit FormatValue(T* val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
if (arg.keyEmpty()) {
FormatValue<void*>((void*)val_).format(arg, cb);
} else {
TryFormatValue<T>::formatOrFail(val_[arg.splitIntKey()], arg, cb);
}
}
private:
T* val_;
};
namespace detail {
// std::array
template <class T, size_t N>
struct IndexableTraits<std::array<T, N>>
: public IndexableTraitsSeq<std::array<T, N>> {
};
// std::vector
template <class T, class A>
struct IndexableTraits<std::vector<T, A>>
: public IndexableTraitsSeq<std::vector<T, A>> {
};
// std::deque
template <class T, class A>
struct IndexableTraits<std::deque<T, A>>
: public IndexableTraitsSeq<std::deque<T, A>> {
};
// std::map with integral keys
template <class K, class T, class C, class A>
struct IndexableTraits<
std::map<K, T, C, A>,
typename std::enable_if<std::is_integral<K>::value>::type>
: public IndexableTraitsAssoc<std::map<K, T, C, A>> {
};
// std::unordered_map with integral keys
template <class K, class T, class H, class E, class A>
struct IndexableTraits<
std::unordered_map<K, T, H, E, A>,
typename std::enable_if<std::is_integral<K>::value>::type>
: public IndexableTraitsAssoc<std::unordered_map<K, T, H, E, A>> {
};
} // namespace detail
// Partial specialization of FormatValue for integer-indexable containers
template <class T>
class FormatValue<
T,
typename detail::IndexableTraits<T>::enabled> {
public:
explicit FormatValue(const T& val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
FormatValue<typename std::decay<
typename detail::IndexableTraits<T>::value_type>::type>(
detail::IndexableTraits<T>::at(
val_, arg.splitIntKey())).format(arg, cb);
}
private:
const T& val_;
};
template <class Container, class Value>
class FormatValue<
detail::DefaultValueWrapper<Container, Value>,
typename detail::IndexableTraits<Container>::enabled> {
public:
explicit FormatValue(const detail::DefaultValueWrapper<Container, Value>& val)
: val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
FormatValue<typename std::decay<
typename detail::IndexableTraits<Container>::value_type>::type>(
detail::IndexableTraits<Container>::at(
val_.container,
arg.splitIntKey(),
val_.defaultValue)).format(arg, cb);
}
private:
const detail::DefaultValueWrapper<Container, Value>& val_;
};
namespace detail {
// Define enabled, key_type, convert from StringPiece to the key types
// that we support
template <class T> struct KeyFromStringPiece;
// std::string
template <>
struct KeyFromStringPiece<std::string> : public FormatTraitsBase {
typedef std::string key_type;
static std::string convert(StringPiece s) {
return s.toString();
}
typedef void enabled;
};
// fbstring
template <>
struct KeyFromStringPiece<fbstring> : public FormatTraitsBase {
typedef fbstring key_type;
static fbstring convert(StringPiece s) {
return s.toFbstring();
}
};
// StringPiece
template <>
struct KeyFromStringPiece<StringPiece> : public FormatTraitsBase {
typedef StringPiece key_type;
static StringPiece convert(StringPiece s) {
return s;
}
};
// Base class for associative types keyed by strings
template <class T> struct KeyableTraitsAssoc : public FormatTraitsBase {
typedef typename T::key_type key_type;
typedef typename T::value_type::second_type value_type;
static const value_type& at(const T& map, StringPiece key) {
return map.at(KeyFromStringPiece<key_type>::convert(key));
}
static const value_type& at(const T& map, StringPiece key,
const value_type& dflt) {
auto pos = map.find(KeyFromStringPiece<key_type>::convert(key));
return pos != map.end() ? pos->second : dflt;
}
};
// Define enabled, key_type, value_type, at() for supported string-keyed
// types
template <class T, class Enabled=void> struct KeyableTraits;
// std::map with string key
template <class K, class T, class C, class A>
struct KeyableTraits<
std::map<K, T, C, A>,
typename KeyFromStringPiece<K>::enabled>
: public KeyableTraitsAssoc<std::map<K, T, C, A>> {
};
// std::unordered_map with string key
template <class K, class T, class H, class E, class A>
struct KeyableTraits<
std::unordered_map<K, T, H, E, A>,
typename KeyFromStringPiece<K>::enabled>
: public KeyableTraitsAssoc<std::unordered_map<K, T, H, E, A>> {
};
} // namespace detail
// Partial specialization of FormatValue for string-keyed containers
template <class T>
class FormatValue<
T,
typename detail::KeyableTraits<T>::enabled> {
public:
explicit FormatValue(const T& val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
FormatValue<typename std::decay<
typename detail::KeyableTraits<T>::value_type>::type>(
detail::KeyableTraits<T>::at(
val_, arg.splitKey())).format(arg, cb);
}
private:
const T& val_;
};
template <class Container, class Value>
class FormatValue<
detail::DefaultValueWrapper<Container, Value>,
typename detail::KeyableTraits<Container>::enabled> {
public:
explicit FormatValue(const detail::DefaultValueWrapper<Container, Value>& val)
: val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
FormatValue<typename std::decay<
typename detail::KeyableTraits<Container>::value_type>::type>(
detail::KeyableTraits<Container>::at(
val_.container,
arg.splitKey(),
val_.defaultValue)).format(arg, cb);
}
private:
const detail::DefaultValueWrapper<Container, Value>& val_;
};
// Partial specialization of FormatValue for pairs
template <class A, class B>
class FormatValue<std::pair<A, B>> {
public:
explicit FormatValue(const std::pair<A, B>& val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
int key = arg.splitIntKey();
switch (key) {
case 0:
FormatValue<typename std::decay<A>::type>(val_.first).format(arg, cb);
break;
case 1:
FormatValue<typename std::decay<B>::type>(val_.second).format(arg, cb);
break;
default:
arg.error("invalid index for pair");
}
}
private:
const std::pair<A, B>& val_;
};
// Partial specialization of FormatValue for tuples
template <class... Args>
class FormatValue<std::tuple<Args...>> {
typedef std::tuple<Args...> Tuple;
public:
explicit FormatValue(const Tuple& val) : val_(val) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
int key = arg.splitIntKey();
arg.enforce(key >= 0, "tuple index must be non-negative");
doFormat(key, arg, cb);
}
private:
static constexpr size_t valueCount = std::tuple_size<Tuple>::value;
template <size_t K, class Callback>
typename std::enable_if<K == valueCount>::type doFormatFrom(
size_t i, FormatArg& arg, Callback& /* cb */) const {
arg.enforce("tuple index out of range, max=", i);
}
template <size_t K, class Callback>
typename std::enable_if<(K < valueCount)>::type
doFormatFrom(size_t i, FormatArg& arg, Callback& cb) const {
if (i == K) {
FormatValue<typename std::decay<
typename std::tuple_element<K, Tuple>::type>::type>(
std::get<K>(val_)).format(arg, cb);
} else {
doFormatFrom<K+1>(i, arg, cb);
}
}
template <class Callback>
void doFormat(size_t i, FormatArg& arg, Callback& cb) const {
return doFormatFrom<0>(i, arg, cb);
}
const Tuple& val_;
};
// Partial specialization of FormatValue for nested Formatters
template <bool containerMode, class... Args,
template <bool, class...> class F>
class FormatValue<F<containerMode, Args...>,
typename std::enable_if<detail::IsFormatter<
F<containerMode, Args...>>::value>::type> {
typedef typename F<containerMode, Args...>::BaseType FormatterValue;
public:
explicit FormatValue(const FormatterValue& f) : f_(f) { }
template <class FormatCallback>
void format(FormatArg& arg, FormatCallback& cb) const {
format_value::formatFormatter(f_, arg, cb);
}
private:
const FormatterValue& f_;
};
/**
* Formatter objects can be appended to strings, and therefore they're
* compatible with folly::toAppend and folly::to.
*/
template <class Tgt, class Derived, bool containerMode, class... Args>
typename std::enable_if<IsSomeString<Tgt>::value>::type toAppend(
const BaseFormatter<Derived, containerMode, Args...>& value, Tgt* result) {
value.appendTo(*result);
}
} // namespace folly
#pragma GCC diagnostic pop