I'm struggling to get boost's stack trace library to interoperate with fmt, the trouble seems to be that I can't quite specialize a boost::stacktrace::basic_stacktrace. Anybody know what the underlying issue is?
#include <fmt/core.h>
#include <boost/stacktrace.hpp>
using BoostTraceStackFrame = std::remove_reference_t<decltype(boost::stacktrace::stacktrace().as_vector().front())>;
template <> struct fmt::formatter<BoostTraceStackFrame> : formatter<string_view>
{
template <typename FORMAT_CONTEXT> auto format(const BoostTraceStackFrame &rhs, FORMAT_CONTEXT &ctx)
{
return fmt::format(ctx.out(), "{}:{}\n", rhs.source_file(), rhs.source_line());
}
};
using BoostTraceType = std::remove_reference_t<decltype(boost::stacktrace::stacktrace())>;
template <> struct fmt::formatter<BoostTraceType> : formatter<string_view>
{
//possibly BoostTraceType = boost::stacktrace::basic_stacktrace ?
template <typename FORMAT_CONTEXT> auto format(const BoostTraceType &rhs, FORMAT_CONTEXT &ctx)
{
return fmt::format(ctx.out(), "{}", fmt::join(rhs.as_vector(), "\n"));
}
};
int main()
{
auto trace = boost::stacktrace::stacktrace();
fmt::print("Foo trace {}",trace);
}
Just three small things:
Missing/wrong headers. You need to include fmt/ranges.h
in order to support formatting ranges.
Wrong overload. The function for formatting into an iterator is fmt::format_to
, not fmt::format
.
These:
using BoostTraceStackFrame = std::remove_reference_t<decltype(boost::stacktrace::stacktrace().as_vector().front())>;
using BoostTraceType = std::remove_reference_t<decltype(boost::stacktrace::stacktrace())>;
are fairly long-winded ways of writing:
using BoostTraceStackFrame = boost::stacktrace::frame;
using BoostTraceType = boost::stacktrace::stacktrace;
And in particular, the problem was that the way you wrote the first one it was boost::stacktrace::frame const
when it needed to not be const
.