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- // 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
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