// Formatting library for C++

//

// Copyright (c) 2012 - 2016, Victor Zverovich

// All rights reserved.

//

// For the license information refer to format.h.

#ifndef FMT_PRINTF_H_

#define FMT_PRINTF_H_

#include <algorithm> // std::fill_n

#include <limits> // std::numeric_limits

#include "ostream.h"

FMT_BEGIN_NAMESPACE

namespace internal {

// An iterator that produces a null terminator on *end. This simplifies parsing

// and allows comparing the performance of processing a null-terminated string

// vs string_view.

template <typename Char>

class null_terminating_iterator {

public:

typedef std::ptrdiff_t difference_type;

typedef Char value_type;

typedef const Char* pointer;

typedef const Char& reference;

typedef std::random_access_iterator_tag iterator_category;

null_terminating_iterator() : ptr_(0), end_(0) {}

FMT_CONSTEXPR null_terminating_iterator(const Char *ptr, const Char *end)

: ptr_(ptr), end_(end) {}

template <typename Range>

FMT_CONSTEXPR explicit null_terminating_iterator(const Range &r)

: ptr_(r.begin()), end_(r.end()) {}

FMT_CONSTEXPR null_terminating_iterator &operator=(const Char *ptr) {

assert(ptr <= end_);

ptr_ = ptr;

return *this;

}

FMT_CONSTEXPR Char operator*() const {

return ptr_ != end_ ? *ptr_ : Char();

}

FMT_CONSTEXPR null_terminating_iterator operator++() {

++ptr_;

return *this;

}

FMT_CONSTEXPR null_terminating_iterator operator++(int) {

null_terminating_iterator result(*this);

++ptr_;

return result;

}

FMT_CONSTEXPR null_terminating_iterator operator--() {

--ptr_;

return *this;

}

FMT_CONSTEXPR null_terminating_iterator operator+(difference_type n) {

return null_terminating_iterator(ptr_ + n, end_);

}

FMT_CONSTEXPR null_terminating_iterator operator-(difference_type n) {

return null_terminating_iterator(ptr_ - n, end_);

}

FMT_CONSTEXPR null_terminating_iterator operator+=(difference_type n) {

ptr_ += n;

return *this;

}

FMT_CONSTEXPR difference_type operator-(

null_terminating_iterator other) const {

return ptr_ - other.ptr_;

}

FMT_CONSTEXPR bool operator!=(null_terminating_iterator other) const {

return ptr_ != other.ptr_;

}

bool operator>=(null_terminating_iterator other) const {

return ptr_ >= other.ptr_;

}

// This should be a friend specialization pointer_from<Char> but the latter

// doesn't compile by gcc 5.1 due to a compiler bug.

template <typename CharT>

friend FMT_CONSTEXPR_DECL const CharT *pointer_from(

null_terminating_iterator<CharT> it);

private:

const Char *ptr_;

const Char *end_;

};

template <typename T>

FMT_CONSTEXPR const T *pointer_from(const T *p) { return p; }

template <typename Char>

FMT_CONSTEXPR const Char *pointer_from(null_terminating_iterator<Char> it) {

return it.ptr_;

}

// DEPRECATED: Parses the input as an unsigned integer. This function assumes

// that the first character is a digit and presence of a non-digit character at

// the end.

// it: an iterator pointing to the beginning of the input range.

template <typename Iterator, typename ErrorHandler>

FMT_CONSTEXPR unsigned parse_nonnegative_int(Iterator &it, ErrorHandler &&eh) {

assert('0' <= *it && *it <= '9');

if (*it == '0') {

++it;

return 0;

}

unsigned value = 0;

// Convert to unsigned to prevent a warning.

unsigned max_int = (std::numeric_limits<int>::max)();

unsigned big = max_int / 10;

do {

// Check for overflow.

if (value > big) {

value = max_int + 1;

break;

}

value = value * 10 + unsigned(*it - '0');

// Workaround for MSVC "setup_exception stack overflow" error:

auto next = it;

++next;

it = next;

} while ('0' <= *it && *it <= '9');

if (value > max_int)

eh.on_error("number is too big");

return value;

}

// Checks if a value fits in int - used to avoid warnings about comparing

// signed and unsigned integers.

template <bool IsSigned>

struct int_checker {

template <typename T>

static bool fits_in_int(T value) {

unsigned max = std::numeric_limits<int>::max();

return value <= max;

}

static bool fits_in_int(bool) { return true; }

};

template <>

struct int_checker<true> {

template <typename T>

static bool fits_in_int(T value) {

return value >= std::numeric_limits<int>::min() &&

value <= std::numeric_limits<int>::max();

}

static bool fits_in_int(int) { return true; }

};

class printf_precision_handler: public function<int> {

public:

template <typename T>

typename std::enable_if<std::is_integral<T>::value, int>::type

operator()(T value) {

if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))

FMT_THROW(format_error("number is too big"));

return static_cast<int>(value);

}

template <typename T>

typename std::enable_if<!std::is_integral<T>::value, int>::type operator()(T) {

FMT_THROW(format_error("precision is not integer"));

return 0;

}

};

// An argument visitor that returns true iff arg is a zero integer.

class is_zero_int: public function<bool> {

public:

template <typename T>

typename std::enable_if<std::is_integral<T>::value, bool>::type

operator()(T value) { return value == 0; }

template <typename T>

typename std::enable_if<!std::is_integral<T>::value, bool>::type

operator()(T) { return false; }

};

template <typename T>

struct make_unsigned_or_bool : std::make_unsigned<T> {};

template <>

struct make_unsigned_or_bool<bool> {

typedef bool type;

};

template <typename T, typename Context>

class arg_converter: public function<void> {

private:

typedef typename Context::char_type Char;

basic_format_arg<Context> &arg_;

typename Context::char_type type_;

public:

arg_converter(basic_format_arg<Context> &arg, Char type)

: arg_(arg), type_(type) {}

void operator()(bool value) {

if (type_ != 's')

operator()<bool>(value);

}

template <typename U>

typename std::enable_if<std::is_integral<U>::value>::type

operator()(U value) {

bool is_signed = type_ == 'd' || type_ == 'i';

typedef typename std::conditional<

std::is_same<T, void>::value, U, T>::type TargetType;

if (const_check(sizeof(TargetType) <= sizeof(int))) {

// Extra casts are used to silence warnings.

if (is_signed) {

arg_ = internal::make_arg<Context>(

static_cast<int>(static_cast<TargetType>(value)));

} else {

typedef typename make_unsigned_or_bool<TargetType>::type Unsigned;

arg_ = internal::make_arg<Context>(

static_cast<unsigned>(static_cast<Unsigned>(value)));

}

} else {

if (is_signed) {

// glibc's printf doesn't sign extend arguments of smaller types:

// std::printf("%lld", -42); // prints "4294967254"

// but we don't have to do the same because it's a UB.

arg_ = internal::make_arg<Context>(static_cast<long long>(value));

} else {

arg_ = internal::make_arg<Context>(

static_cast<typename make_unsigned_or_bool<U>::type>(value));

}

}

}

template <typename U>

typename std::enable_if<!std::is_integral<U>::value>::type operator()(U) {

// No coversion needed for non-integral types.

}

};

// Converts an integer argument to T for printf, if T is an integral type.

// If T is void, the argument is converted to corresponding signed or unsigned

// type depending on the type specifier: 'd' and 'i' - signed, other -

// unsigned).

template <typename T, typename Context, typename Char>

void convert_arg(basic_format_arg<Context> &arg, Char type) {

visit_format_arg(arg_converter<T, Context>(arg, type), arg);

}

// Converts an integer argument to char for printf.

template <typename Context>

class char_converter: public function<void> {

private:

basic_format_arg<Context> &arg_;

public:

explicit char_converter(basic_format_arg<Context> &arg) : arg_(arg) {}

template <typename T>

typename std::enable_if<std::is_integral<T>::value>::type

operator()(T value) {

typedef typename Context::char_type Char;

arg_ = internal::make_arg<Context>(static_cast<Char>(value));

}

template <typename T>

typename std::enable_if<!std::is_integral<T>::value>::type operator()(T) {

// No coversion needed for non-integral types.

}

};

// Checks if an argument is a valid printf width specifier and sets

// left alignment if it is negative.

template <typename Char>

class printf_width_handler: public function<unsigned> {

private:

typedef basic_format_specs<Char> format_specs;

format_specs &spec_;

public:

explicit printf_width_handler(format_specs &spec) : spec_(spec) {}

template <typename T>

typename std::enable_if<std::is_integral<T>::value, unsigned>::type

operator()(T value) {

typedef typename internal::int_traits<T>::main_type UnsignedType;

UnsignedType width = static_cast<UnsignedType>(value);

if (internal::is_negative(value)) {

spec_.align_ = ALIGN_LEFT;

width = 0 - width;

}

unsigned int_max = std::numeric_limits<int>::max();

if (width > int_max)

FMT_THROW(format_error("number is too big"));

return static_cast<unsigned>(width);

}

template <typename T>

typename std::enable_if<!std::is_integral<T>::value, unsigned>::type

operator()(T) {

FMT_THROW(format_error("width is not integer"));

return 0;

}

};

template <typename Char, typename Context>

void printf(basic_buffer<Char> &buf, basic_string_view<Char> format,

basic_format_args<Context> args) {

Context(std::back_inserter(buf), format, args).format();

}

} // namespace internal

using internal::printf; // For printing into memory_buffer.

template <typename Range>

class printf_arg_formatter;

template <

typename OutputIt, typename Char,

typename ArgFormatter =

printf_arg_formatter<back_insert_range<internal::basic_buffer<Char>>>>

class basic_printf_context;

/**

\rst

The ``printf`` argument formatter.

\endrst

*/

template <typename Range>

class printf_arg_formatter:

public internal::function<

typename internal::arg_formatter_base<Range>::iterator>,

public internal::arg_formatter_base<Range> {

private:

typedef typename Range::value_type char_type;

typedef decltype(internal::declval<Range>().begin()) iterator;

typedef internal::arg_formatter_base<Range> base;

typedef basic_printf_context<iterator, char_type> context_type;

context_type &context_;

void write_null_pointer(char) {

this->spec()->type = 0;

this->write("(nil)");

}

void write_null_pointer(wchar_t) {

this->spec()->type = 0;

this->write(L"(nil)");

}

public:

typedef typename base::format_specs format_specs;

/**

\rst

Constructs an argument formatter object.

*buffer* is a reference to the output buffer and *spec* contains format

specifier information for standard argument types.

\endrst

*/

printf_arg_formatter(internal::basic_buffer<char_type> &buffer,

format_specs &spec, context_type &ctx)

: base(back_insert_range<internal::basic_buffer<char_type>>(buffer), &spec,

ctx.locale()),

context_(ctx) {}

template <typename T>

typename std::enable_if<std::is_integral<T>::value, iterator>::type

operator()(T value) {

// MSVC2013 fails to compile separate overloads for bool and char_type so

// use std::is_same instead.

if (std::is_same<T, bool>::value) {

format_specs &fmt_spec = *this->spec();

if (fmt_spec.type != 's')

return base::operator()(value ? 1 : 0);

fmt_spec.type = 0;

this->write(value != 0);

} else if (std::is_same<T, char_type>::value) {

format_specs &fmt_spec = *this->spec();

if (fmt_spec.type && fmt_spec.type != 'c')

return (*this)(static_cast<int>(value));

fmt_spec.flags = 0;

fmt_spec.align_ = ALIGN_RIGHT;

return base::operator()(value);

} else {

return base::operator()(value);

}

return this->out();

}

template <typename T>

typename std::enable_if<std::is_floating_point<T>::value, iterator>::type

operator()(T value) {

return base::operator()(value);

}

/** Formats a null-terminated C string. */

iterator operator()(const char *value) {

if (value)

base::operator()(value);

else if (this->spec()->type == 'p')

write_null_pointer(char_type());

else

this->write("(null)");

return this->out();

}

/** Formats a null-terminated wide C string. */

iterator operator()(const wchar_t *value) {

if (value)

base::operator()(value);

else if (this->spec()->type == 'p')

write_null_pointer(char_type());

else

this->write(L"(null)");

return this->out();

}

iterator operator()(basic_string_view<char_type> value) {

return base::operator()(value);

}

iterator operator()(monostate value) {

return base::operator()(value);

}

/** Formats a pointer. */

iterator operator()(const void *value) {

if (value)

return base::operator()(value);

this->spec()->type = 0;

write_null_pointer(char_type());

return this->out();

}

/** Formats an argument of a custom (user-defined) type. */

iterator operator()(typename basic_format_arg<context_type>::handle handle) {

handle.format(context_);

return this->out();

}

};

template <typename T>

struct printf_formatter {

template <typename ParseContext>

auto parse(ParseContext &ctx) -> decltype(ctx.begin()) { return ctx.begin(); }

template <typename FormatContext>

auto format(const T &value, FormatContext &ctx) -> decltype(ctx.out()) {

internal::format_value(internal::get_container(ctx.out()), value);

return ctx.out();

}

};

/** This template formats data and writes the output to a writer. */

template <typename OutputIt, typename Char, typename ArgFormatter>

class basic_printf_context :

// Inherit publicly as a workaround for the icc bug

// https://software.intel.com/en-us/forums/intel-c-compiler/topic/783476.

public internal::context_base<

OutputIt, basic_printf_context<OutputIt, Char, ArgFormatter>, Char> {

public:

/** The character type for the output. */

typedef Char char_type;

template <typename T>

struct formatter_type { typedef printf_formatter<T> type; };

private:

typedef internal::context_base<OutputIt, basic_printf_context, Char> base;

typedef typename base::format_arg format_arg;

typedef basic_format_specs<char_type> format_specs;

typedef internal::null_terminating_iterator<char_type> iterator;

void parse_flags(format_specs &spec, iterator &it);

// Returns the argument with specified index or, if arg_index is equal

// to the maximum unsigned value, the next argument.

format_arg get_arg(

iterator it,

unsigned arg_index = (std::numeric_limits<unsigned>::max)());

// Parses argument index, flags and width and returns the argument index.

unsigned parse_header(iterator &it, format_specs &spec);

public:

/**

\rst

Constructs a ``printf_context`` object. References to the arguments and

the writer are stored in the context object so make sure they have

appropriate lifetimes.

\endrst

*/

basic_printf_context(OutputIt out, basic_string_view<char_type> format_str,

basic_format_args<basic_printf_context> args)

: base(out, format_str, args) {}

using base::parse_context;

using base::out;

using base::advance_to;

/** Formats stored arguments and writes the output to the range. */

void format();

};

template <typename OutputIt, typename Char, typename AF>

void basic_printf_context<OutputIt, Char, AF>::parse_flags(

format_specs &spec, iterator &it) {

for (;;) {

switch (*it++) {

case '-':

spec.align_ = ALIGN_LEFT;

break;

case '+':

spec.flags |= SIGN_FLAG | PLUS_FLAG;

break;

case '0':

spec.fill_ = '0';

break;

case ' ':

spec.flags |= SIGN_FLAG;

break;

case '#':

spec.flags |= HASH_FLAG;

break;

default:

--it;

return;

}

}

}

template <typename OutputIt, typename Char, typename AF>

typename basic_printf_context<OutputIt, Char, AF>::format_arg

basic_printf_context<OutputIt, Char, AF>::get_arg(

iterator it, unsigned arg_index) {

(void)it;

if (arg_index == std::numeric_limits<unsigned>::max())

return this->do_get_arg(this->parse_context().next_arg_id());

return base::get_arg(arg_index - 1);

}

template <typename OutputIt, typename Char, typename AF>

unsigned basic_printf_context<OutputIt, Char, AF>::parse_header(

iterator &it, format_specs &spec) {

unsigned arg_index = std::numeric_limits<unsigned>::max();

char_type c = *it;

if (c >= '0' && c <= '9') {

// Parse an argument index (if followed by '$') or a width possibly

// preceded with '0' flag(s).

internal::error_handler eh;

unsigned value = parse_nonnegative_int(it, eh);

if (*it == '$') { // value is an argument index

++it;

arg_index = value;

} else {

if (c == '0')

spec.fill_ = '0';

if (value != 0) {

// Nonzero value means that we parsed width and don't need to

// parse it or flags again, so return now.

spec.width_ = value;

return arg_index;

}

}

}

parse_flags(spec, it);

// Parse width.

if (*it >= '0' && *it <= '9') {

internal::error_handler eh;

spec.width_ = parse_nonnegative_int(it, eh);

} else if (*it == '*') {

++it;

spec.width_ = visit_format_arg(

internal::printf_width_handler<char_type>(spec), get_arg(it));

}

return arg_index;

}

template <typename OutputIt, typename Char, typename AF>

void basic_printf_context<OutputIt, Char, AF>::format() {

auto &buffer = internal::get_container(this->out());

auto start = iterator(this->parse_context());

auto it = start;

using internal::pointer_from;

while (*it) {

char_type c = *it++;

if (c != '%') continue;

if (*it == c) {

buffer.append(pointer_from(start), pointer_from(it));

start = ++it;

continue;

}

buffer.append(pointer_from(start), pointer_from(it) - 1);

format_specs spec;

spec.align_ = ALIGN_RIGHT;

// Parse argument index, flags and width.

unsigned arg_index = parse_header(it, spec);

// Parse precision.

if (*it == '.') {

++it;

if ('0' <= *it && *it <= '9') {

internal::error_handler eh;

spec.precision = static_cast<int>(parse_nonnegative_int(it, eh));

} else if (*it == '*') {

++it;

spec.precision =

visit_format_arg(internal::printf_precision_handler(), get_arg(it));

} else {

spec.precision = 0;

}

}

format_arg arg = get_arg(it, arg_index);

if (spec.has(HASH_FLAG) && visit_format_arg(internal::is_zero_int(), arg))

spec.flags = static_cast<uint_least8_t>(spec.flags & (~internal::to_unsigned<int>(HASH_FLAG)));

if (spec.fill_ == '0') {

if (arg.is_arithmetic())

spec.align_ = ALIGN_NUMERIC;

else

spec.fill_ = ' '; // Ignore '0' flag for non-numeric types.

}

// Parse length and convert the argument to the required type.

using internal::convert_arg;

switch (*it++) {

case 'h':

if (*it == 'h')

convert_arg<signed char>(arg, *++it);

else

convert_arg<short>(arg, *it);

break;

case 'l':

if (*it == 'l')

convert_arg<long long>(arg, *++it);

else

convert_arg<long>(arg, *it);

break;

case 'j':

convert_arg<intmax_t>(arg, *it);

break;

case 'z':

convert_arg<std::size_t>(arg, *it);

break;

case 't':

convert_arg<std::ptrdiff_t>(arg, *it);

break;

case 'L':

// printf produces garbage when 'L' is omitted for long double, no

// need to do the same.

break;

default:

--it;

convert_arg<void>(arg, *it);

}

// Parse type.

if (!*it)

FMT_THROW(format_error("invalid format string"));

spec.type = static_cast<char>(*it++);

if (arg.is_integral()) {

// Normalize type.

switch (spec.type) {

case 'i': case 'u':

spec.type = 'd';

break;

case 'c':

// TODO: handle wchar_t better?

visit_format_arg(

internal::char_converter<basic_printf_context>(arg), arg);

break;

}

}

start = it;

// Format argument.

visit_format_arg(AF(buffer, spec, *this), arg);

}

buffer.append(pointer_from(start), pointer_from(it));

}

template <typename Buffer>

struct basic_printf_context_t {

typedef basic_printf_context<

std::back_insert_iterator<Buffer>, typename Buffer::value_type> type;

};

typedef basic_printf_context_t<internal::buffer>::type printf_context;

typedef basic_printf_context_t<internal::wbuffer>::type wprintf_context;

typedef basic_format_args<printf_context> printf_args;

typedef basic_format_args<wprintf_context> wprintf_args;

/**

\rst

Constructs an `~fmt::format_arg_store` object that contains references to

arguments and can be implicitly converted to `~fmt::printf_args`.

\endrst

*/

template<typename... Args>

inline format_arg_store<printf_context, Args...>

make_printf_args(const Args &... args) { return {args...}; }

/**

\rst

Constructs an `~fmt::format_arg_store` object that contains references to

arguments and can be implicitly converted to `~fmt::wprintf_args`.

\endrst

*/

template<typename... Args>

inline format_arg_store<wprintf_context, Args...>

make_wprintf_args(const Args &... args) { return {args...}; }

template <typename S, typename Char = FMT_CHAR(S)>

inline std::basic_string<Char>

vsprintf(const S &format,

basic_format_args<typename basic_printf_context_t<

internal::basic_buffer<Char>>::type> args) {

basic_memory_buffer<Char> buffer;

printf(buffer, to_string_view(format), args);

return to_string(buffer);

}

/**

\rst

Formats arguments and returns the result as a string.

**Example**::

std::string message = fmt::sprintf("The answer is %d", 42);

\endrst

*/

template <typename S, typename... Args>

inline FMT_ENABLE_IF_T(

internal::is_string<S>::value, std::basic_string<FMT_CHAR(S)>)

sprintf(const S &format, const Args & ... args) {

internal::check_format_string<Args...>(format);

typedef internal::basic_buffer<FMT_CHAR(S)> buffer;

typedef typename basic_printf_context_t<buffer>::type context;

format_arg_store<context, Args...> as{ args... };

return vsprintf(to_string_view(format),

basic_format_args<context>(as));

}

template <typename S, typename Char = FMT_CHAR(S)>

inline int vfprintf(std::FILE *f, const S &format,

basic_format_args<typename basic_printf_context_t<

internal::basic_buffer<Char>>::type> args) {

basic_memory_buffer<Char> buffer;

printf(buffer, to_string_view(format), args);

std::size_t size = buffer.size();

return std::fwrite(

buffer.data(), sizeof(Char), size, f) < size ? -1 : static_cast<int>(size);

}

/**

\rst

Prints formatted data to the file *f*.

**Example**::

fmt::fprintf(stderr, "Don't %s!", "panic");

\endrst

*/

template <typename S, typename... Args>

inline FMT_ENABLE_IF_T(internal::is_string<S>::value, int)

fprintf(std::FILE *f, const S &format, const Args & ... args) {

internal::check_format_string<Args...>(format);

typedef internal::basic_buffer<FMT_CHAR(S)> buffer;

typedef typename basic_printf_context_t<buffer>::type context;

format_arg_store<context, Args...> as{ args... };

return vfprintf(f, to_string_view(format),

basic_format_args<context>(as));

}

template <typename S, typename Char = FMT_CHAR(S)>

inline int vprintf(const S &format,

basic_format_args<typename basic_printf_context_t<

internal::basic_buffer<Char>>::type> args) {

return vfprintf(stdout, to_string_view(format), args);

}

/**

\rst

Prints formatted data to ``stdout``.

**Example**::

fmt::printf("Elapsed time: %.2f seconds", 1.23);

\endrst

*/

template <typename S, typename... Args>

inline FMT_ENABLE_IF_T(internal::is_string<S>::value, int)

printf(const S &format_str, const Args & ... args) {

internal::check_format_string<Args...>(format_str);

typedef internal::basic_buffer<FMT_CHAR(S)> buffer;

typedef typename basic_printf_context_t<buffer>::type context;

format_arg_store<context, Args...> as{ args... };

return vprintf(to_string_view(format_str),

basic_format_args<context>(as));

}

template <typename S, typename Char = FMT_CHAR(S)>

inline int vfprintf(std::basic_ostream<Char> &os,

const S &format,

basic_format_args<typename basic_printf_context_t<

internal::basic_buffer<Char>>::type> args) {

basic_memory_buffer<Char> buffer;

printf(buffer, to_string_view(format), args);

internal::write(os, buffer);

return static_cast<int>(buffer.size());

}

/**

\rst

Prints formatted data to the stream *os*.

**Example**::

fmt::fprintf(cerr, "Don't %s!", "panic");

\endrst

*/

template <typename S, typename... Args>

inline FMT_ENABLE_IF_T(internal::is_string<S>::value, int)

fprintf(std::basic_ostream<FMT_CHAR(S)> &os,

const S &format_str, const Args & ... args) {

internal::check_format_string<Args...>(format_str);

typedef internal::basic_buffer<FMT_CHAR(S)> buffer;

typedef typename basic_printf_context_t<buffer>::type context;

format_arg_store<context, Args...> as{ args... };

return vfprintf(os, to_string_view(format_str),

basic_format_args<context>(as));

}

FMT_END_NAMESPACE

#endif // FMT_PRINTF_H_