https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65188
Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-02-24
CC| |manu at gcc dot gnu.org
Summary|diagnostic: missing: |improve error for member
|reference to non-static |operator applied to
|member function must be |non-class type
|called |
Ever confirmed|0 |1
--- Comment #1 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
How does Clang message help in this case? The suggested fix 'c.f().a' will just
give 'invalid use of void type'
Of course, g++ could be better, as this testcase shows:
class C {
public:
void g() {};
C& f() {};
int a;
} c;
void g2();
C&f2();
int foo(char **p, char **q) { return (p-q).a; }
int bar() { return c.f.a; }
int baz() { return c.g.a; }
int bar2() { return f2.a; }
int baz2() { return g2.a; }
g++:
test.cc:10:44: error: request for member ‘a’ in ‘((((long int)p) - ((long
int)q)) (ceiling /) 8l)’, which is of non-class type ‘long int’
int foo(char **p, char **q) { return (p-q).a; }
^
test.cc: In function ‘int bar()’:
test.cc:11:20: error: ‘c.C::f’ does not have class type
int bar() { return c.f.a; }
^
test.cc: In function ‘int baz()’:
test.cc:12:20: error: ‘c.C::g’ does not have class type
int baz() { return c.g.a; }
^
test.cc: In function ‘int bar2()’:
test.cc:13:24: error: request for member ‘a’ in ‘f2’, which is of non-class
type ‘C&()’
int bar2() { return f2.a; }
^
test.cc: In function ‘int baz2()’:
test.cc:14:24: error: request for member ‘a’ in ‘g2’, which is of non-class
type ‘void()’
int baz2() { return g2.a; }
^
Possible improvements:
1) Consistency: all these errors should print the same message.
2) Location: the location should point to the expression that is not of class
type.
3) No pretty-printing of arbitrary expressions: If the expression is a name or
a declaration, print it; otherwise, print "request for member 'a' in expression
of non-class type 'long int'"
4) For types that have declarations, we could point to the declaration with a
note: 'c.C::f' declared here
For your testcase, it could be:
10.C:2:23: error: request for member in ‘c.C::f’, which is of non-class type
'void (C::)()'
int main() { return c.f.a; }
^
10.C:1:19: note: declared here
class C { public: void f() {} } c;
^
