Narrowing conversions in C++0x. Is it just me, or does this sound like a breaking change?

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I ran into this breaking change when I used GCC. The compiler printed an error for code like this:

void foo(const unsigned long long &i)
{
    unsigned int a[2] = {i & 0xFFFFFFFF, i >> 32};
}

In function void foo(const long long unsigned int&):

error: narrowing conversion of (((long long unsigned int)i) & 4294967295ull) from long long unsigned int to unsigned int inside { }

error: narrowing conversion of (((long long unsigned int)i) >> 32) from long long unsigned int to unsigned int inside { }

Fortunately, the error messages were straightforward and the fix was simple:

void foo(const unsigned long long &i)
{
    unsigned int a[2] = {static_cast<unsigned int>(i & 0xFFFFFFFF),
            static_cast<unsigned int>(i >> 32)};
}

The code was in an external library, with only two occurrences in one file. I don’t think the breaking change will affect much code. Novices might get confused, though.

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