== comparison of string literals, and their usage

[diniz]

Le 06/04/2019 à 16:07, AltFunction1 via Digitalmars-d-learn a écrit :
> On Friday, 5 April 2019 at 14:49:50 UTC, diniz wrote:
>> Hello,
>>
>> Since literal strings are interned (and immutable), can I count on the fact 
>> that they are compared (==) by pointer?
> 
> No. "==" performs a full array comparison and "is" is apparently simplified at 
> compile time. In the compiler there's no notion of string literal as a special 
> expression. It's always a StringExp. See https://d.godbolt.org/z/K5R6u6.
> 
> However you're right to say that literal are not duplicated.

Thank you very much.

So, I still could store and use and compare string pointers myself [1], and get 
valid results, meaning: pointer equality implies (literal) string equality. Or 
am I wrong? The point is, the parser, operating on an array of prescanned 
lexemes,  will constantly check whether a valid lexeme is present simply by 
checking the lexeme "class". I don't want that to be a real string comp, too 
expesensive and for no gain.

[1] As in the second comp of your example:
void main()
{
     auto c2 =  "one" == "two";
     auto c1 =  "one".ptr is "two".ptr;
}
-- 
diniz {la vita e estranj}