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Boost-for-Android-Prebuilt/boost-1_72_0/include/boost/convert/printf.hpp
r4sas 93de5720b8
add boost 1.72.0
Signed-off-by: r4sas <r4sas@i2pmail.org>
2020-02-29 22:43:48 +00:00

88 lines
3.4 KiB
C++

// Copyright (c) 2009-2016 Vladimir Batov.
// Use, modification and distribution are subject to the Boost Software License,
// Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
#ifndef BOOST_CONVERT_PRINTF_HPP
#define BOOST_CONVERT_PRINTF_HPP
#include <boost/convert/base.hpp>
#include <boost/make_default.hpp>
#include <boost/mpl/vector.hpp>
#include <boost/mpl/find.hpp>
#include <boost/range/as_literal.hpp>
#include <string>
#include <cstdio>
namespace boost { namespace cnv
{
struct printf;
}}
struct boost::cnv::printf : boost::cnv::cnvbase<boost::cnv::printf>
{
using this_type = boost::cnv::printf;
using base_type = boost::cnv::cnvbase<this_type>;
using base_type::operator();
template<typename in_type>
cnv::range<char*>
to_str(in_type value_in, char* buf) const
{
char const* fmt = pformat(pos<in_type>());
int const num_chars = snprintf(buf, bufsize_, fmt, precision_, value_in);
bool const success = num_chars < bufsize_;
return cnv::range<char*>(buf, success ? (buf + num_chars) : buf);
}
template<typename string_type, typename out_type>
void
str_to(cnv::range<string_type> range, optional<out_type>& result_out) const
{
out_type result = boost::make_default<out_type>();
int const num_read = sscanf(&*range.begin(), format(pos<out_type>()), &result);
if (num_read == 1)
result_out = result;
}
private:
template<typename Type> int pos() const
{
using managed_types = boost::mpl::vector<double, float,
int, unsigned int,
short int, unsigned short int,
long int, unsigned long int>;
using type_iterator = typename boost::mpl::find<managed_types, Type>::type;
using type_pos = typename type_iterator::pos;
return type_pos::value;
}
char const* pformat(int pos) const
{
static char const* d_fmt[] = { "%.*f", "%.*f", "%.*d", "%.*u", "%.*hd", "%.*hu", "%.*ld", "%.*lu" }; // Must match managed_types
static char const* x_fmt[] = { "%.*f", "%.*f", "%.*x", "%.*x", "%.*hx", "%.*hx", "%.*lx", "%.*lx" }; // Must match managed_types
static char const* o_fmt[] = { "%.*f", "%.*f", "%.*o", "%.*o", "%.*ho", "%.*ho", "%.*lo", "%.*lo" }; // Must match managed_types
char const* fmt = base_ == boost::cnv::base::dec ? d_fmt[pos]
: base_ == boost::cnv::base::hex ? x_fmt[pos]
: base_ == boost::cnv::base::oct ? o_fmt[pos]
: (BOOST_ASSERT(0), nullptr);
return fmt;
}
char const* format(int pos) const
{
static char const* d_fmt[] = { "%f", "%f", "%d", "%u", "%hd", "%hu", "%ld", "%lu" }; // Must match managed_types
static char const* x_fmt[] = { "%f", "%f", "%x", "%x", "%hx", "%hx", "%lx", "%lx" }; // Must match managed_types
static char const* o_fmt[] = { "%f", "%f", "%o", "%o", "%ho", "%ho", "%lo", "%lo" }; // Must match managed_types
char const* fmt = base_ == boost::cnv::base::dec ? d_fmt[pos]
: base_ == boost::cnv::base::hex ? x_fmt[pos]
: base_ == boost::cnv::base::oct ? o_fmt[pos]
: (BOOST_ASSERT(0), nullptr);
return fmt;
}
};
#endif // BOOST_CONVERT_PRINTF_HPP