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A customisation point that applies a concept-preserving property to an object.

constexpr unspecified require = unspecified;

The name require denotes a customisation point object. The expression boost::asio::require(E, P0, Pn...) for some subexpressions E and P0, and where Pn... represents N subexpressions (where N is 0 or more, and with types T = decay_t<decltype(E)> and Prop0 = decay_t<decltype(P0)>) is expression-equivalent to:


Header: boost/asio/require.hpp

Convenience header: boost/asio.hpp