Annex D (normative) Compatibility features [depr]

D.9 Binders [depr.lib.binders]

D.9.2 bind1st [depr.lib.bind.1st]

template <class Fn, class T> binder1st<Fn> bind1st(const Fn& fn, const T& x);

Returns: binder1st<Fn>(fn, typename Fn::first_argument_type(x)).