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copied!<p>I wouldn't be all that surprised if somebody gets caught out by something like:</p> <pre><code>float ra[] = {0, CHAR_MAX, SHORT_MAX, INT_MAX, LONG_MAX}; </code></pre> <p>(on my implementation, the last two don't produce the same result when converted back to int/long, hence are narrowing)</p> <p>I don't remember ever writing this, though. It's only useful if an approximation to the limits is useful for something.</p> <p>This seems at least vaguely plausible too:</p> <pre><code>void some_function(int val1, int val2) { float asfloat[] = {val1, val2}; // not in C++0x double asdouble[] = {val1, val2}; // not in C++0x int asint[] = {val1, val2}; // OK // now do something with the arrays } </code></pre> <p>but it isn't entirely convincing, because if I know I have exactly two values, why put them in arrays rather than just <code>float floatval1 = val1, floatval1 = val2;</code>? What's the motivation, though, why that should compile (and work, provided the loss of precision is within acceptable accuracy for the program), while <code>float asfloat[] = {val1, val2};</code> shouldn't? Either way I'm initializing two floats from two ints, it's just that in one case the two floats happen to be members of an aggregate.</p> <p>That seems particularly harsh in cases where a non-constant expression results in a narrowing conversion even though (on a particular implementation), all values of the source type are representable in the destination type and convertible back to their original values:</p> <pre><code>char i = something(); static_assert(CHAR_BIT == 8); double ra[] = {i}; // how is this worse than using a constant value? </code></pre> <p>Assuming there's no bug, presumably the fix is always to make the conversion explicit. Unless you're doing something odd with macros, I think an array initializer only appears close to the type of the array, or at least to something representing the type, which could be dependent on a template parameter. So a cast should be easy, if verbose.</p>

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