fprintf

Synopsis

template <class FormatString, class T1, ..., class Tn>
int fprintf(FILE *f, T1 a1, ..., Tn an);

Description

Wrapper of the fprintf function of the C library. It takes the format string as a compile-time string, which is an boost::metaparse::string. It type-checks the arguments based on the format string. When type-checking fails, this function emits a compilation error. When type-checking succeeds, this function calls the sprintf function of the C library. This thin wrapper is likely to be inlined in which case it has no runtime overhead compared to using fprintf without type-checking.

#include <mpllibs/safe_printf/fprintf.hpp>

Expression semantics

For any s boost::metaparse::string, f FILE pointer and a1 ... an runtime objects:

mpllibs::safe_printf::fprintf<s>(f, a1, ..., an)

When the number and types of a1 ... an are correct according to s, the format string, it is equivalent to

std::fprintf(f, boost::mpl::c_str<s>::type::value, a1, ..., an)

otherwise it is a compilation error.

Example

FILE *f = std::fopen("test.txt", "wt");
safe_printf::fprintf<BOOST_METAPARSE_STRING("%d %d\n")>(f, 11, 13);
fclose(f);

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