Why is an initialiser containing a string literal valid to initialise a `char` array?

Question

It turns out that char c[] = {"a"}; is completely valid in both C++03 and C++11.

I would not expect it to be, because it is an array of char not of char const*, and I would expect a brace-initialiser to require a compatible type for each of its "items". It has one item, and that's a char const* not a char.

So what makes this initialisation valid? And is there a rationale for it being so?

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^{Similarly, char c[] = {"aa"}; compiles, and printing c results in the output "aa".}

^{I would expect char c[]{"a"} to be valid in C++11, of course, but it's not the same! Similarly, char c[] = {'a'} is obvious in both, as is char c[] = "a".}

Answer 1

Although it may not necessarily be intuitive, it simply is allowed; there's a distinct rule for it in both standards:

[2003: 8.5.2/1]: A char array (whether plain char, signed char, or unsigned char) can be initialized by a string-literal (optionally enclosed in braces); a wchar_t array can be initialized by a wide string-literal (optionally enclosed in braces); successive characters of the string-literal initialize the members of the array. [..]

[n3290: 8.5.2/1]: A char array (whether plain char, signed char, or unsigned char), char16_t array, char32_t array, or wchar_t array can be initialized by a narrow character literal, char16_t string literal, char32_t string literal, or wide string literal, respectively, or by an appropriately-typed string literal enclosed in braces. Successive characters of the value of the string literal initialize the elements of the array.

I can't explain why the committee made it this way, though.