https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79350
Bug ID: 79350
Summary: "explicit" deduction guides don't work
Product: gcc
Version: 7.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mike at spertus dot com
Target Milestone: ---
When I compile the following code with gcc-7-20170122,
template<typename T> struct S {};
template<typename T>
explicit S(T) -> S<T *>;
I get the error
error: decl-specifier in declaration of deduction guide
explicit S(T) -> S<T *>;
^~~~~~~~
test.cpp:3:1: error: ‘explicit’ outside class declaration
This is currently a bug because the current standard draft N4618 allows an
optional "explicit" in the deduction-guide grammar production
