rexylib/include/rexy/detail/string_appender.hpp

47 lines
1.3 KiB
C++

#ifndef REXY_STRING_APPENDER_HPP
#define REXY_STRING_APPENDER_HPP
#include "../expression.hpp"
#include "../traits.hpp"
#include <utility> //forward
namespace rexy::detail{
template<class Targ>
struct string_appender
{
private:
Targ& m_targ;
public:
constexpr string_appender(Targ& t)noexcept:
m_targ(t){}
template<class L, class R>
constexpr void operator()(const binary_expression<L,R>& expr)
noexcept(noexcept((*this)(expr.left())) && noexcept((*this)(expr.right())))
{
(*this)(expr.left());
(*this)(expr.right());
}
template<class L>
constexpr void operator()(const unary_expression<L>& expr)
noexcept(noexcept((*this)(expr.left())))
{
(*this)(expr.left());
}
template<class Val, std::enable_if_t<!rexy::is_template_derived_type<Val,binary_expression>::value,int> = 0, class = decltype(std::declval<Val>().length())>
constexpr void operator()(Val&& v)
{
m_targ.append(std::forward<Val>(v).get(), std::forward<Val>(v).length());
}
template<class Val, std::enable_if_t<!rexy::is_template_derived_type<Val,binary_expression>::value,void*> = nullptr, class = decltype(std::declval<Val>().size())>
constexpr void operator()(Val&& v)
{
m_targ.append(std::forward<Val>(v).get(), std::forward<Val>(v).size());
}
};
}
#endif