Nathan Ridge <zeratul976@xxxxxxxxxxx> writes:
> Consider the following fragment of invalid code:
>
> struct A
> {
> struct B {};
>
> int g();
>
> B f() { return g(); }
> };
>
> GCC 4.5's error message is "error: conversion from 'int' to non-scalar type 'A::B' requested".
>
> GCC 4.6's error message is "error: could not convert 'A::g()' to 'A::B'".
>
> The 4.6 error message no longer mentions the actual type, int, that
> cannot be converted to the declared return type, insteading mentioning
> the expression yielding that type, A::g().
>
> What is the rationale for this change?
>
> I think 4.5's error message is more useful because you can see from it
> exactly what conversion (int to A::B) is failing. With 4.6's error message,
> to find out why the conversion is failing you now have to look up the
> return value of A::g() in your code.
>
> The difference becomes more pronounced with more complex examples.
> For example, for the code in PR 49003,
>
> GCC 4.5: "error: conversion from 'vector::const_iterator' to non-scalar type 'vector::iterator' requested"
>
> GCC 4.6: "error: could not convert '((const block*)this)->block::v.vector::begin()' to 'vector::iterator'"
>
> Quite clearly, the 4.5 error message is better.
>
> Having said that, I think the phrasing of the 4.6 error is better,
> so the best option would be:
>
> error: could not convert 'vector::const_iterator' to 'vector::iterator'
>
> Thoughts?
Please file a bug report. See http://gcc.gnu.org/bugs/ . Thanks.
Ian
