std::projected_value_t - cppreference.com

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`template< std::indirectly_readable I, std::indirectly_regular_unary_invocable<I> Proj > using projected_value_t = std::remove_cvref_t<std::invoke_result_t<Proj&, std::iter_value_t<I>&>>;`		(since C++26)

The alias template projected_value_t obtains the value type by stripping any reference and its topmost cv-qualifiers of the result type of applying Proj to std::iter_value_t<I>&.

projected_value_t is used to determine the default value type in some algorithms such as ranges::contains.

Template parameters

I	-	an indirectly readable type
Proj	-	projection applied to an lvalue reference to value type of `I`

Notes

Feature-test macro	Value	Std	Feature
`__cpp_lib_algorithm_default_value_type`	`202403L`	(C++26)	default template type for algorithm values using `std::projected_value_t`

Template parameters

Notes

Example

See also

	computes the result of invoking a callable object on the result of dereferencing some set of `indirectly_readable` types (alias template)[edit]
	helper template for specifying the constraints on algorithms that accept projections (class template) [edit]