eagine/valid_if/io.hpp Source File

OGLplus (0.59.0) a C++ wrapper for rendering APIs

  
 #ifndef EAGINE_VALID_IF_IO_HPP
 #define EAGINE_VALID_IF_IO_HPP
  
 #include "base.hpp"
 #include <iosfwd>
  
 namespace eagine {
  
 template <typename T, typename P, typename L>
 auto operator<<(std::ostream& out, const basic_valid_if<T, P, L>& v) -> auto& {
     if(v.is_valid()) {
         return out << v.value_anyway();
     }
     return out << "∅";
 }
  
 } // namespace eagine
  
 #endif // EAGINE_VALID_IF_IO_HPP

eagine

Common code is placed in this namespace.

Definition: eagine.hpp:21

base.hpp

eagine::operator<<

static auto operator<<(std::ostream &out, const identifier_name< M > &n) -> std::ostream &

Operator for writing identifier_name into output streams.

Definition: identifier.hpp:159

eagine::basic_valid_if

Basic template for conditionally-valid values.

Definition: base.hpp:86