3
Terms and definitions
[intro.defs]
3.54
[defns.signature.templ.friend]
signature
⟨friend function template with constraint involving enclosing template parameters⟩ name, parameter-type-list, return type, enclosing class,
signature
(
[defns.
signature.
template.
head]
) of the
template-head
, and trailing
requires-clause
(if any)