12 Overloading [over]

12.3 Overload resolution [over.match]

12.3.1 Candidate functions and argument lists [over.match.funcs] Initialization by list-initialization [over.match.list]

When objects of non-aggregate class type T are list-initialized such that [dcl.init.list] specifies that overload resolution is performed according to the rules in this subclause, overload resolution selects the constructor in two phases:
If the initializer list has no elements and T has a default constructor, the first phase is omitted.
In copy-list-initialization, if an explicit constructor is chosen, the initialization is ill-formed.
This differs from other situations ([over.match.ctor], [over.match.copy]), where only converting constructors are considered for copy-initialization.
This restriction only applies if this initialization is part of the final result of overload resolution.
end note