<cstdio> support

The following functions analogous to those from <cstdio> are provided:

#include <boost/decimal/cstdio.hpp>

namespace boost {
namespace decimal {

template <typename... Dec>
int snprintf(char* buffer, std::size_t buf_size, const char* format, Dec... value) noexcept;

template <typename... Dec>
int fprintf(std::FILE* buffer, const char* format, Dec... values) noexcept;

template <typename... Dec>
int printf(const char* format, Dec... values) noexcept;

} //namespace decimal
} //namespace boost

Type Modifiers

The type modifiers to be used are:

  • "H" for decimal32_t

  • "D" for decimal64_t

  • "DD" for decimal128_t

The remaining specifications of cstdio are the same as usual:

  • "g" or "G" for general format

  • "e" or "E" for scientific format

  • "f" for fixed format

  • "a" or "A" for hex format

The uppercase format will return with all applicable values in uppercase (e.g. 3.14E+02 vs 3.14e+02)

Examples

Here are some example formats:

  • "%Hg" will print a decimal32_t in general format

  • "%.3De" will print a decimal64_t in scientific format with 3 digits of precision (e.g. 1.234e+05)

  • "%.5DDA" will print a decimal128_t in hex format with 5 digits of precision and all letters will be capitalized (e.g. 1.F2C34P+02 vs 1.f2c34p+02)

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