Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
template <class T> typename add_rvalue_reference<T>::type declval() noexcept; // as unevaluated operand
C++ Standard Reference: C++11 20.2.4 [declval].
Header: #include
<boost/type_traits/declval.hpp>
or #include <boost/type_traits.hpp>
The function template declval
is used when a value of a certain type is required in a type computation
context. For example, the type of the result of adding an int
and a float can be obtained
with the expression decltype( declval<int>()
+ declval<float>() ).