Is my compiler incorrect?

Question

Whenever I run this in the compiler I get 1 returned to me. However, I've been told that this shouldn't return 1 and that my compiler is wrong and can't be trusted.

Is my friend right in that the compiler's I use are giving me the incorrect answer, or is this supposed to return 1?

#include <iostream>
#include <string>

int main()
{
    bool lol = "abc" < "abcd";
    std::cout << lol;
    return 0;
}

You compare pointers to those strings locations. Formally that's undefined behaviour. You probably want to use `std::strcmp()` or `std::string`s instead. — HolyBlackCat, Jul 15 '18 at 19:48
If your compiler returns `1`, there is something gone wrong during compilation. The compiler does not execute the source code, but … well … compiles it. — too honest for this site, Jul 15 '18 at 19:58

Angew is no longer proud of SO · Answer 1 · 2018-07-15T19:58:04.007

2

The code has Undefined Behaviour, because it's using an oredering comparison operator on two pointers (the address of the string literal "abc" and that of the string literal "abcd") which are not part of the same array. It can therefore do absolutely anything.

edited Jul 15 '18 at 19:58

answered Jul 15 '18 at 19:48

Angew is no longer proud of SO

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why is this pointer comparison? Isn't it supposed to be `string` comparison? – hiimdaosui Jul 15 '18 at 19:52
@It'scominghome But the code is doing `<`, which is not allowed cross-array. – Angew is no longer proud of SO Jul 15 '18 at 19:53
3

@hiimdaosui String literals decay to pointers. – Angew is no longer proud of SO Jul 15 '18 at 19:53

Is my compiler incorrect?

1 Answers1