// tinyformat.h
// Copyright (C) 2011, Chris Foster [chris42f (at) gmail (d0t) com]
//
// Boost Software License - Version 1.0
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//------------------------------------------------------------------------------
// Tinyformat: A minimal type safe printf replacement
//
// tinyformat.h is a type safe printf replacement library in a single C++
// header file. Design goals include:
//
// * Type safety and extensibility for user defined types.
// * C99 printf() compatibility, to the extent possible using std::ostream
// * Simplicity and minimalism. A single header file to include and distribute
// with your projects.
// * Augment rather than replace the standard stream formatting mechanism
// * C++98 support, with optional C++11 niceties
//
//
// Main interface example usage
// ----------------------------
//
// To print a date to std::cout:
//
// std::string weekday = "Wednesday";
// const char* month = "July";
// size_t day = 27;
// long hour = 14;
// int min = 44;
//
// tfm::printf("%s, %s %d, %.2d:%.2d\n", weekday, month, day, hour, min);
//
// The strange types here emphasize the type safety of the interface; it is
// possible to print a std::string using the "%s" conversion, and a
// size_t using the "%d" conversion. A similar result could be achieved
// using either of the tfm::format() functions. One prints on a user provided
// stream:
//
// tfm::format(std::cerr, "%s, %s %d, %.2d:%.2d\n",
// weekday, month, day, hour, min);
//
// The other returns a std::string:
//
// std::string date = tfm::format("%s, %s %d, %.2d:%.2d\n",
// weekday, month, day, hour, min);
// std::cout << date;
//
// These are the three primary interface functions. There is also a
// convenience function printfln() which appends a newline to the usual result
// of printf() for super simple logging.
//
//
// User defined format functions
// -----------------------------
//
// Simulating variadic templates in C++98 is pretty painful since it requires
// writing out the same function for each desired number of arguments. To make
// this bearable tinyformat comes with a set of macros which are used
// internally to generate the API, but which may also be used in user code.
//
// The three macros TINYFORMAT_ARGTYPES(n), TINYFORMAT_VARARGS(n) and
// TINYFORMAT_PASSARGS(n) will generate a list of n argument types,
// type/name pairs and argument names respectively when called with an integer
// n between 1 and 16. We can use these to define a macro which generates the
// desired user defined function with n arguments. To generate all 16 user
// defined function bodies, use the macro TINYFORMAT_FOREACH_ARGNUM. For an
// example, see the implementation of printf() at the end of the source file.
//
// Sometimes it's useful to be able to pass a list of format arguments through
// to a non-template function. The FormatList class is provided as a way to do
// this by storing the argument list in a type-opaque way. Continuing the
// example from above, we construct a FormatList using makeFormatList():
//
// FormatListRef formatList = tfm::makeFormatList(weekday, month, day, hour,
// min);
//
// The format list can now be passed into any non-template function and used
// via a call to the vformat() function:
//
// tfm::vformat(std::cout, "%s, %s %d, %.2d:%.2d\n", formatList);
//
//
// Additional API information
// --------------------------
//
// Error handling: Define TINYFORMAT_ERROR to customize the error handling for
// format strings which are unsupported or have the wrong number of format
// specifiers (calls assert() by default).
//
// User defined types: Uses operator<< for user defined types by default.
// Overload formatValue() for more control.
#pragma once
#include <algorithm>
#include <cassert>
#include <iostream>
#include <sstream>
namespace paddle {
namespace string {
namespace tinyformat {
#ifndef TINYFORMAT_ERROR
#define TINYFORMAT_ERROR(reason) assert(0 && reason)
#endif
//------------------------------------------------------------------------------
namespace detail {
// Test whether type T1 is convertible to type T2
template <typename T1, typename T2>
struct is_convertible {
private:
// two types of different size
struct fail {
char dummy[2];
};
struct succeed {
char dummy;
};
// Try to convert a T1 to a T2 by plugging into tryConvert
static fail tryConvert(...);
static succeed tryConvert(const T2 &);
static const T1 &makeT1();
public:
// Standard trick: the (...) version of tryConvert will be chosen from
// the overload set only if the version taking a T2 doesn't match.
// Then we compare the sizes of the return types to check which
// function matched. Very neat, in a disgusting kind of way :)
static const bool value = sizeof(tryConvert(makeT1())) == sizeof(succeed);
};
// Format the value by casting to type fmtT. This default implementation
// should never be called.
template <typename T, typename fmtT,
bool convertible = is_convertible<T, fmtT>::value>
struct formatValueAsType {
static void invoke(std::ostream & /*out*/, const T & /*value*/) { assert(0); }
};
// Specialized version for types that can actually be converted to fmtT, as
// indicated by the "convertible" template parameter.
template <typename T, typename fmtT>
struct formatValueAsType<T, fmtT, true> {
static void invoke(std::ostream &out, const T &value) {
out << static_cast<fmtT>(value);
}
};
// Convert an arbitrary type to integer. The version with convertible=false
// throws an error.
template <typename T, bool convertible = is_convertible<T, int>::value>
struct convertToInt {
static int invoke(const T & /*value*/) {
TINYFORMAT_ERROR(
"tinyformat: Cannot convert from argument type to "
"integer for use as variable width or precision");
return 0;
}
};
// Specialization for convertToInt when conversion is possible
template <typename T>
struct convertToInt<T, true> {
static int invoke(const T &value) { return static_cast<int>(value); }
};
// Format at most ntrunc characters to the given stream.
template <typename T>
inline void formatTruncated(std::ostream &out, const T &value, int ntrunc) {
std::ostringstream tmp;
tmp << value;
std::string result = tmp.str();
out.write(result.c_str(),
(std::min)(ntrunc, static_cast<int>(result.size())));
}
#define TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR(type) \
inline void formatTruncated(std::ostream &out, type *value, int ntrunc) { \
std::streamsize len = 0; \
while (len < ntrunc && value[len] != 0) ++len; \
out.write(value, len); \
}
// Overload for const char* and char*. Could overload for signed & unsigned
// char too, but these are technically unneeded for printf compatibility.
TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR(const char)
TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR(char)
#undef TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR
} // namespace detail
//------------------------------------------------------------------------------
// Variable formatting functions. May be overridden for user-defined types if
// desired.
/// Format a value into a stream, delegating to operator<< by default.
///
/// Users may override this for their own types. When this function is called,
/// the stream flags will have been modified according to the format string.
/// The format specification is provided in the range [fmtBegin, fmtEnd). For
/// truncating conversions, ntrunc is set to the desired maximum number of
/// characters, for example "%.7s" calls formatValue with ntrunc = 7.
///
/// By default, formatValue() uses the usual stream insertion operator
/// operator<< to format the type T, with special cases for the %c and %p
/// conversions.
template <typename T>
inline void formatValue(std::ostream &out, const char * /*fmtBegin*/,
const char *fmtEnd, int ntrunc, const T &value) {
// The mess here is to support the %c and %p conversions: if these
// conversions are active we try to convert the type to a char or const
// void* respectively and format that instead of the value itself. For the
// %p conversion it's important to avoid dereferencing the pointer, which
// could otherwise lead to a crash when printing a dangling (const char*).
const bool canConvertToChar = detail::is_convertible<T, char>::value;
const bool canConvertToVoidPtr =
detail::is_convertible<T, const void *>::value;
if (canConvertToChar && *(fmtEnd - 1) == 'c')
detail::formatValueAsType<T, char>::invoke(out, value);
else if (canConvertToVoidPtr && *(fmtEnd - 1) == 'p')
detail::formatValueAsType<T, const void *>::invoke(out, value);
else if (ntrunc >= 0) {
// Take care not to overread C strings in truncating conversions like
// "%.4s" where at most 4 characters may be read.
detail::formatTruncated(out, value, ntrunc);
} else
out << value;
}
// Overloaded version for char types to support printing as an integer
#define TINYFORMAT_DEFINE_FORMATVALUE_CHAR(charType) \
inline void formatValue(std::ostream &out, const char * /*fmtBegin*/, \
const char *fmtEnd, int /**/, charType value) { \
switch (*(fmtEnd - 1)) { \
case 'u': \
case 'd': \
case 'i': \
case 'o': \
case 'X': \
case 'x': \
out << static_cast<int>(value); \
break; \
default: \
out << value; \
break; \
} \
}
// per 3.9.1: char, signed char and unsigned char are all distinct types
TINYFORMAT_DEFINE_FORMATVALUE_CHAR(char)
TINYFORMAT_DEFINE_FORMATVALUE_CHAR(signed char)
TINYFORMAT_DEFINE_FORMATVALUE_CHAR(unsigned char)
#undef TINYFORMAT_DEFINE_FORMATVALUE_CHAR
//------------------------------------------------------------------------------
// Tools for emulating variadic templates in C++98. The basic idea here is
// stolen from the boost preprocessor metaprogramming library and cut down to
// be just general enough for what we need.
#define TINYFORMAT_ARGTYPES(n) TINYFORMAT_ARGTYPES_##n
#define TINYFORMAT_VARARGS(n) TINYFORMAT_VARARGS_##n
#define TINYFORMAT_PASSARGS(n) TINYFORMAT_PASSARGS_##n
#define TINYFORMAT_PASSARGS_TAIL(n) TINYFORMAT_PASSARGS_TAIL_##n
// To keep it as transparent as possible, the macros below have been generated
// using python via the excellent cog.py code generation script. This avoids
// the need for a bunch of complex (but more general) preprocessor tricks as
// used in boost.preprocessor.
//
// To rerun the code generation in place, use `cog.py -r tinyformat.h`
// (see http://nedbatchelder.com/code/cog). Alternatively you can just create
// extra versions by hand.
/*[[[cog
maxParams = 16
def makeCommaSepLists(lineTemplate, elemTemplate, startInd=1):
for j in range(startInd,maxParams+1):
list = ', '.join([elemTemplate % {'i':i} for i in range(startInd,j+1)])
cog.outl(lineTemplate % {'j':j, 'list':list})
makeCommaSepLists('#define TINYFORMAT_ARGTYPES_%(j)d %(list)s',
'class T%(i)d')
cog.outl()
makeCommaSepLists('#define TINYFORMAT_VARARGS_%(j)d %(list)s',
'const T%(i)d& v%(i)d')
cog.outl()
makeCommaSepLists('#define TINYFORMAT_PASSARGS_%(j)d %(list)s', 'v%(i)d')
cog.outl()
cog.outl('#define TINYFORMAT_PASSARGS_TAIL_1')
makeCommaSepLists('#define TINYFORMAT_PASSARGS_TAIL_%(j)d , %(list)s',
'v%(i)d', startInd = 2)
cog.outl()
cog.outl('#define TINYFORMAT_FOREACH_ARGNUM(m) \\\n ' +
' '.join(['m(%d)' % (j,) for j in range(1,maxParams+1)]))
]]]*/
#define TINYFORMAT_ARGTYPES_1 class T1
#define TINYFORMAT_ARGTYPES_2 class T1, class T2
#define TINYFORMAT_ARGTYPES_3 class T1, class T2, class T3
#define TINYFORMAT_ARGTYPES_4 class T1, class T2, class T3, class T4
#define TINYFORMAT_ARGTYPES_5 class T1, class T2, class T3, class T4, class T5
#define TINYFORMAT_ARGTYPES_6 \
class T1, class T2, class T3, class T4, class T5, class T6
#define TINYFORMAT_ARGTYPES_7 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7
#define TINYFORMAT_ARGTYPES_8 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8
#define TINYFORMAT_ARGTYPES_9 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9
#define TINYFORMAT_ARGTYPES_10 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9, class T10
#define TINYFORMAT_ARGTYPES_11 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9, class T10, class T11
#define TINYFORMAT_ARGTYPES_12 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9, class T10, class T11, class T12
#define TINYFORMAT_ARGTYPES_13 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9, class T10, class T11, class T12, class T13
#define TINYFORMAT_ARGTYPES_14 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9, class T10, class T11, class T12, class T13, \
class T14
#define TINYFORMAT_ARGTYPES_15 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9, class T10, class T11, class T12, class T13, \
class T14, class T15
#define TINYFORMAT_ARGTYPES_16 \
class T1, class T2, class T3, class T4, class T5, class T6, class T7, \
class T8, class T9, class T10, class T11, class T12, class T13, \
class T14, class T15, class T16
#define TINYFORMAT_VARARGS_1 const T1 &v1
#define TINYFORMAT_VARARGS_2 const T1 &v1, const T2 &v2
#define TINYFORMAT_VARARGS_3 const T1 &v1, const T2 &v2, const T3 &v3
#define TINYFORMAT_VARARGS_4 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4
#define TINYFORMAT_VARARGS_5 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5
#define TINYFORMAT_VARARGS_6 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6
#define TINYFORMAT_VARARGS_7 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7
#define TINYFORMAT_VARARGS_8 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8
#define TINYFORMAT_VARARGS_9 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9
#define TINYFORMAT_VARARGS_10 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9, const T10 &v10
#define TINYFORMAT_VARARGS_11 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9, const T10 &v10, \
const T11 &v11
#define TINYFORMAT_VARARGS_12 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9, const T10 &v10, \
const T11 &v11, const T12 &v12
#define TINYFORMAT_VARARGS_13 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9, const T10 &v10, \
const T11 &v11, const T12 &v12, const T13 &v13
#define TINYFORMAT_VARARGS_14 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9, const T10 &v10, \
const T11 &v11, const T12 &v12, const T13 &v13, const T14 &v14
#define TINYFORMAT_VARARGS_15 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9, const T10 &v10, \
const T11 &v11, const T12 &v12, const T13 &v13, const T14 &v14, \
const T15 &v15
#define TINYFORMAT_VARARGS_16 \
const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, \
const T6 &v6, const T7 &v7, const T8 &v8, const T9 &v9, const T10 &v10, \
const T11 &v11, const T12 &v12, const T13 &v13, const T14 &v14, \
const T15 &v15, const T16 &v16
#define TINYFORMAT_PASSARGS_1 v1
#define TINYFORMAT_PASSARGS_2 v1, v2
#define TINYFORMAT_PASSARGS_3 v1, v2, v3
#define TINYFORMAT_PASSARGS_4 v1, v2, v3, v4
#define TINYFORMAT_PASSARGS_5 v1, v2, v3, v4, v5
#define TINYFORMAT_PASSARGS_6 v1, v2, v3, v4, v5, v6
#define TINYFORMAT_PASSARGS_7 v1, v2, v3, v4, v5, v6, v7
#define TINYFORMAT_PASSARGS_8 v1, v2, v3, v4, v5, v6, v7, v8
#define TINYFORMAT_PASSARGS_9 v1, v2, v3, v4, v5, v6, v7, v8, v9
#define TINYFORMAT_PASSARGS_10 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10
#define TINYFORMAT_PASSARGS_11 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11
#define TINYFORMAT_PASSARGS_12 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12
#define TINYFORMAT_PASSARGS_13 \
v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13
#define TINYFORMAT_PASSARGS_14 \
v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14
#define TINYFORMAT_PASSARGS_15 \
v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15
#define TINYFORMAT_PASSARGS_16 \
v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15, v16
#define TINYFORMAT_PASSARGS_TAIL_1
#define TINYFORMAT_PASSARGS_TAIL_2 , v2
#define TINYFORMAT_PASSARGS_TAIL_3 , v2, v3
#define TINYFORMAT_PASSARGS_TAIL_4 , v2, v3, v4
#define TINYFORMAT_PASSARGS_TAIL_5 , v2, v3, v4, v5
#define TINYFORMAT_PASSARGS_TAIL_6 , v2, v3, v4, v5, v6
#define TINYFORMAT_PASSARGS_TAIL_7 , v2, v3, v4, v5, v6, v7
#define TINYFORMAT_PASSARGS_TAIL_8 , v2, v3, v4, v5, v6, v7, v8
#define TINYFORMAT_PASSARGS_TAIL_9 , v2, v3, v4, v5, v6, v7, v8, v9
#define TINYFORMAT_PASSARGS_TAIL_10 , v2, v3, v4, v5, v6, v7, v8, v9, v10
#define TINYFORMAT_PASSARGS_TAIL_11 , v2, v3, v4, v5, v6, v7, v8, v9, v10, v11
#define TINYFORMAT_PASSARGS_TAIL_12 \
, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12
#define TINYFORMAT_PASSARGS_TAIL_13 \
, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13
#define TINYFORMAT_PASSARGS_TAIL_14 \
, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14
#define TINYFORMAT_PASSARGS_TAIL_15 \
, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15
#define TINYFORMAT_PASSARGS_TAIL_16 \
, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15, v16
#define TINYFORMAT_FOREACH_ARGNUM(m) \
m(1) m(2) m(3) m(4) m(5) m(6) m(7) m(8) m(9) m(10) m(11) m(12) m(13) m(14) \
m(15) m(16)
//[[[end]]]
namespace detail {
// Type-opaque holder for an argument to format(), with associated actions on
// the type held as explicit function pointers. This allows FormatArg's for
// each argument to be allocated as a homogenous array inside FormatList
// whereas a naive implementation based on inheritance does not.
class FormatArg {
public:
FormatArg() {}
template <typename T>
FormatArg(const T &value)
: m_value(static_cast<const void *>(&value)),
m_formatImpl(&formatImpl<T>),
m_toIntImpl(&toIntImpl<T>) {}
void format(std::ostream &out, const char *fmtBegin, const char *fmtEnd,
int ntrunc) const {
m_formatImpl(out, fmtBegin, fmtEnd, ntrunc, m_value);
}
int toInt() const { return m_toIntImpl(m_value); }
private:
template <typename T>
static void formatImpl(std::ostream &out, const char *fmtBegin,
const char *fmtEnd, int ntrunc, const void *value) {
formatValue(out, fmtBegin, fmtEnd, ntrunc, *static_cast<const T *>(value));
}
template <typename T>
static int toIntImpl(const void *value) {
return convertToInt<T>::invoke(*static_cast<const T *>(value));
}
const void *m_value;
void (*m_formatImpl)(std::ostream &out, const char *fmtBegin,
const char *fmtEnd, int ntrunc, const void *value);
int (*m_toIntImpl)(const void *value);
};
// Parse and return an integer from the string c, as atoi()
// On return, c is set to one past the end of the integer.
inline int parseIntAndAdvance(const char *&c) {
int i = 0;
for (; *c >= '0' && *c <= '9'; ++c) i = 10 * i + (*c - '0');
return i;
}
// Print literal part of format string and return next format spec
// position.
//
// Skips over any occurrences of '%%', printing a literal '%' to the
// output. The position of the first % character of the next
// nontrivial format spec is returned, or the end of string.
inline const char *printFormatStringLiteral(std::ostream &out,
const char *fmt) {
const char *c = fmt;
for (;; ++c) {
switch (*c) {
case '\0':
out.write(fmt, c - fmt);
return c;
case '%':
out.write(fmt, c - fmt);
if (*(c + 1) != '%') return c;
// for "%%", tack trailing % onto next literal section.
fmt = ++c;
break;
default:
break;
}
}
}
// Parse a format string and set the stream state accordingly.
//
// The format mini-language recognized here is meant to be the one from C99,
// with the form "%[flags][width][.precision][length]type".
//
// Formatting options which can't be natively represented using the ostream
// state are returned in spacePadPositive (for space padded positive numbers)
// and ntrunc (for truncating conversions). argIndex is incremented if
// necessary to pull out variable width and precision . The function returns a
// pointer to the character after the end of the current format spec.
inline const char *streamStateFromFormat(std::ostream &out,
bool &spacePadPositive, int &ntrunc,
const char *fmtStart,
const detail::FormatArg *formatters,
int &argIndex, int numFormatters) {
if (*fmtStart != '%') {
TINYFORMAT_ERROR(
"tinyformat: Not enough conversion specifiers in format string");
return fmtStart;
}
// Reset stream state to defaults.
out.width(0);
out.precision(6);
out.fill(' ');
// Reset most flags; ignore irrelevant unitbuf & skipws.
out.unsetf(std::ios::adjustfield | std::ios::basefield |
std::ios::floatfield | std::ios::showbase | std::ios::boolalpha |
std::ios::showpoint | std::ios::showpos | std::ios::uppercase);
bool precisionSet = false;
bool widthSet = false;
int widthExtra = 0;
const char *c = fmtStart + 1;
// 1) Parse flags
for (;; ++c) {
switch (*c) {
case '#':
out.setf(std::ios::showpoint | std::ios::showbase);
continue;
case '0':
// overridden by left alignment ('-' flag)
if (!(out.flags() & std::ios::left)) {
// Use internal padding so that numeric values are
// formatted correctly, eg -00010 rather than 000-10
out.fill('0');
out.setf(std::ios::internal, std::ios::adjustfield);
}
continue;
case '-':
out.fill(' ');
out.setf(std::ios::left, std::ios::adjustfield);
continue;
case ' ':
// overridden by show positive sign, '+' flag.
if (!(out.flags() & std::ios::showpos)) spacePadPositive = true;
continue;
case '+':
out.setf(std::ios::showpos);
spacePadPositive = false;
widthExtra = 1;
continue;
default:
break;
}
break;
}
// 2) Parse width
if (*c >= '0' && *c <= '9') {
widthSet = true;
out.width(parseIntAndAdvance(c));
}
if (*c == '*') {
widthSet = true;
int width = 0;
if (argIndex < numFormatters)
width = formatters[argIndex++].toInt();
else
TINYFORMAT_ERROR(
"tinyformat: Not enough arguments to read variable width");
if (width < 0) {
// negative widths correspond to '-' flag set
out.fill(' ');
out.setf(std::ios::left, std::ios::adjustfield);
width = -width;
}
out.width(width);
++c;
}
// 3) Parse precision
if (*c == '.') {
++c;
int precision = 0;
if (*c == '*') {
++c;
if (argIndex < numFormatters)
precision = formatters[argIndex++].toInt();
else
TINYFORMAT_ERROR(
"tinyformat: Not enough arguments to read variable precision");
} else {
if (*c >= '0' && *c <= '9')
precision = parseIntAndAdvance(c);
else if (*c == '-') // negative precisions ignored, treated as zero.
parseIntAndAdvance(++c);
}
out.precision(precision);
precisionSet = true;
}
// 4) Ignore any C99 length modifier
while (*c == 'l' || *c == 'h' || *c == 'L' || *c == 'j' || *c == 'z' ||
*c == 't')
++c;
// 5) We're up to the conversion specifier character.
// Set stream flags based on conversion specifier (thanks to the
// boost::format class for forging the way here).
bool intConversion = false;
switch (*c) {
case 'u':
case 'd':
case 'i':
out.setf(std::ios::dec, std::ios::basefield);
intConversion = true;
break;
case 'o':
out.setf(std::ios::oct, std::ios::basefield);
intConversion = true;
break;
case 'X':
out.setf(std::ios::uppercase);
case 'x':
case 'p':
out.setf(std::ios::hex, std::ios::basefield);
intConversion = true;
break;
case 'E':
out.setf(std::ios::uppercase);
case 'e':
out.setf(std::ios::scientific, std::ios::floatfield);
out.setf(std::ios::dec, std::ios::basefield);
break;
case 'F':
out.setf(std::ios::uppercase);
case 'f':
out.setf(std::ios::fixed, std::ios::floatfield);
break;
case 'G':
out.setf(std::ios::uppercase);
case 'g':
out.setf(std::ios::dec, std::ios::basefield);
// As in boost::format, let stream decide float format.
out.flags(out.flags() & ~std::ios::floatfield);
break;
case 'a':
case 'A':
TINYFORMAT_ERROR(
"tinyformat: the %a and %A conversion specs "
"are not supported");
break;
case 'c':
// Handled as special case inside formatValue()
break;
case 's':
if (precisionSet) ntrunc = static_cast<int>(out.precision());
// Make %s print booleans as "true" and "false"
out.setf(std::ios::boolalpha);
break;
case 'n':
// Not supported - will cause problems!
TINYFORMAT_ERROR("tinyformat: %n conversion spec not supported");
break;
case '\0':
TINYFORMAT_ERROR(
"tinyformat: Conversion spec incorrectly "
"terminated by end of string");
return c;
default:
break;
}
if (intConversion && precisionSet && !widthSet) {
// "precision" for integers gives the minimum number of digits (to be
// padded with zeros on the left). This isn't really supported by the
// iostreams, but we can approximately simulate it with the width if
// the width isn't otherwise used.
out.width(out.precision() + widthExtra);
out.setf(std::ios::internal, std::ios::adjustfield);
out.fill('0');
}
return c + 1;
}
//------------------------------------------------------------------------------
inline void formatImpl(std::ostream &out, const char *fmt,
const detail::FormatArg *formatters, int numFormatters) {
// Saved stream state
std::streamsize origWidth = out.width();
std::streamsize origPrecision = out.precision();
std::ios::fmtflags origFlags = out.flags();
char origFill = out.fill();
for (int argIndex = 0; argIndex < numFormatters; ++argIndex) {
// Parse the format string
fmt = printFormatStringLiteral(out, fmt);
bool spacePadPositive = false;
int ntrunc = -1;
const char *fmtEnd =
streamStateFromFormat(out, spacePadPositive, ntrunc, fmt, formatters,
argIndex, numFormatters);
if (argIndex >= numFormatters) {
// Check args remain after reading any variable width/precision
TINYFORMAT_ERROR("tinyformat: Not enough format arguments");
return;
}
const FormatArg &arg = formatters[argIndex];
// Format the arg into the stream.
if (!spacePadPositive)
arg.format(out, fmt, fmtEnd, ntrunc);
else {
// The following is a special case with no direct correspondence
// between stream formatting and the printf() behaviour. Simulate
// it crudely by formatting into a temporary string stream and
// munging the resulting string.
std::ostringstream tmpStream;
tmpStream.copyfmt(out);
tmpStream.setf(std::ios::showpos);
arg.format(tmpStream, fmt, fmtEnd, ntrunc);
std::string result = tmpStream.str(); // allocates... yuck.
for (size_t i = 0, iend = result.size(); i < iend; ++i)
if (result[i] == '+') result[i] = ' ';
out << result;
}
fmt = fmtEnd;
}
// Print remaining part of format string.
fmt = printFormatStringLiteral(out, fmt);
if (*fmt != '\0')
TINYFORMAT_ERROR(
"tinyformat: Too many conversion specifiers in format string");
// Restore stream state
out.width(origWidth);
out.precision(origPrecision);
out.flags(origFlags);
out.fill(origFill);
}
} // namespace detail
/// List of template arguments format(), held in a type-opaque way.
///
/// A const reference to FormatList (typedef'd as FormatListRef) may be
/// conveniently used to pass arguments to non-template functions: All type
/// information has been stripped from the arguments, leaving just enough of a
/// common interface to perform formatting as required.
class FormatList {
public:
FormatList(detail::FormatArg *formatters, int N)
: m_formatters(formatters), m_N(N) {}
friend void vformat(std::ostream &out, const char *fmt,
const FormatList &list);
private:
const detail::FormatArg *m_formatters;
int m_N;
};
/// Reference to type-opaque format list for passing to vformat()
typedef const FormatList &FormatListRef;
namespace detail {
// Format list subclass with fixed storage to avoid dynamic allocation
template <int N>
class FormatListN : public FormatList {
public:
template <typename... Args>
FormatListN(const Args &... args)
: FormatList(&m_formatterStore[0], N),
m_formatterStore{FormatArg(args)...} {
static_assert(sizeof...(args) == N, "Number of args must be N");
}
private:
FormatArg m_formatterStore[N];
};
// Special 0-arg version - MSVC says zero-sized C array in struct is nonstandard
template <>
class FormatListN<0> : public FormatList {
public:
FormatListN() : FormatList(0, 0) {}
};
} // namespace detail
//------------------------------------------------------------------------------
// Primary API functions
/// Make type-agnostic format list from list of template arguments.
///
/// The exact return type of this function is an implementation detail and
/// shouldn't be relied upon. Instead it should be stored as a FormatListRef:
///
/// FormatListRef formatList = makeFormatList( /*...*/ );
template <typename... Args>
detail::FormatListN<sizeof...(Args)> makeFormatList(const Args &... args) {
return detail::FormatListN<sizeof...(args)>(args...);
}
/// Format list of arguments to the stream according to the given format string.
///
/// The name vformat() is chosen for the semantic similarity to vprintf(): the
/// list of format arguments is held in a single function argument.
inline void vformat(std::ostream &out, const char *fmt, FormatListRef list) {
detail::formatImpl(out, fmt, list.m_formatters, list.m_N);
}
/// Format list of arguments to the stream according to given format string.
template <typename... Args>
void format(std::ostream &out, const char *fmt, const Args &... args) {
vformat(out, fmt, makeFormatList(args...));
}
/// Format list of arguments according to the given format string and return
/// the result as a string.
template <typename... Args>
std::string format(const char *fmt, const Args &... args) {
std::ostringstream oss;
format(oss, fmt, args...);
return oss.str();
}
/// Format list of arguments to std::cout, according to the given format string
template <typename... Args>
void printf(const char *fmt, const Args &... args) {
format(std::cout, fmt, args...);
}
template <typename... Args>
void printfln(const char *fmt, const Args &... args) {
format(std::cout, fmt, args...);
std::cout << '\n';
}
} // namespace tinyformat
} // namespace string
} // namespace paddle