cbeam::convert::has_insertion_operator< T, typename > Struct Template Reference

The has_insertion_operator trait provides static meta-information about whether a type T has overloaded the operator<< for insertion into an output stream. More...

#include <string.hpp>

Inheritance diagram for cbeam::convert::has_insertion_operator< T, typename >:

Collaboration diagram for cbeam::convert::has_insertion_operator< T, typename >:

Detailed Description

template<typename T, typename = void>
struct cbeam::convert::has_insertion_operator< T, typename >

The has_insertion_operator trait provides static meta-information about whether a type T has overloaded the operator<< for insertion into an output stream.

This trait is useful for template metaprogramming and generic programming, allowing you to write code that works differently depending on whether a type can be streamed or not.

Template Parameters:

• T: The type to be checked for the existence of an overload for operator<<.
• U: (optional) An unused template parameter used to enable SFINAE (Substitution Failure Is Not An Error).

Member Types:

• value: A static constant bool member that is true if and only if T has an overload for operator<<, and false otherwise.

Specializations:

• The primary template is std::false_type, indicating that by default, types do not have an overload for operator<<.
• A template specialization exists for types T for which a valid overload for operator<< is found. This specialization uses std::void_t<decltype(std::declval<std::ostream&>() << std::declval<T>())> to ensure that the overload is actually callable.

Example Usage:

template <typename T>
void print_value(const T& value) {
  if constexpr (has_insertion_operator<T>::value) {
    std::cout << value;
  } else {
    // Handle types without an insertion operator here...
  }
}

See also:

• std::ostream
• operator<<
• std::enable_if
• std::declval
• std::void_t

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The documentation for this struct was generated from the following file:

• include/cbeam/convert/string.hpp