https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70384
Bug ID: 70384
Summary: Unhelpful warnings on invalid initializations
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: gcc at magfr dot user.lysator.liu.se
Target Milestone: ---
Created attachment 38074
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38074&action=edit
ex.cpp
Consider the following source (ex.cpp):
void f(int&);
void g(long t) {
f(t);
}
Compiling this gives the error
ex.cpp: In function 'void g(long int)':
ex.cpp:3:5: error: invalid initialization of non-const reference of type 'int&'
from an rvalue of type 'int'
f(t);
^
ex.cpp:1:6: note: initializing argument 1 of 'void f(int&)'
void f(int&);
^
and I think that error message is unhelpful.
invalid initialization of non-const reference of type 'int&' from an rvalue of
type 'int'
While this is true in some sense - the long input gets converted to an rvalue
int that isn't feasible as an argument to f - I still think the error message
in 4.4.6 was more helpful when it comes to correcting the error:
invalid initialization of reference of type ‘int&’ from expression of type
‘long int’
so, would it be possible to type the original type as the source type?
For reference clang++ (3.7.0) outputs
candidate function not viable: no known conversion from 'long' to 'int &' for
1st argument
and that is also helpful when it comes to fixing the problem.
