C++ keywords: typename

 

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C++ keywords

alignas alignof and and_eq asm auto bitand bitor bool break case catch char char16_t char32_t class compl const constexpr const_cast continue decltype default delete do double dynamic_cast else	enum explicit export extern false float for friend goto if inline int long mutable namespace new noexcept not not_eq nullptr operator or or_eq private protected public register reinterpret_cast	return short signed sizeof static static_assert static_cast struct switch template this thread_local throw true try typedef typeid typename union unsigned using virtual void volatile wchar_t while xor xor_eq
Identifiers with special meaning
override
final

 

Usage

• In a class template or function template, typename can be used as an alternative to class to declare templated types.
• Inside a template definition, typename can be used to declare that a dependent name is a type.

Example

template <typename T>
void foo (const std::vector<T> &v)
{
    // std::vector<T>::const_iterator is a dependent name,
    // so using it as a type requires the addition of the
    // typename keyword
    typename std::vector<T>::const_iterator it = v.begin();
}