Talk:String (C++)
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[edit] mem usage?
I just had a young programmer tell me that an uninitialized std::string uses less memory than an initialized one. Is that true? (I guess that would depend on the implementation; but consider, for example gcc) The code I found suspect was:
class blah {
private:
std:string name;
public:
blah (std:string in) {
if (!in.empty()) name = in; // claimed savings of memory
}
};
linas (talk) 03:31, 27 January 2008 (UTC)
- That sounds bogus to me. Even if you don't touch
name, it gets initialized at the beginning of the constructor. You can always look at the source, though. —Ben FrantzDale (talk) 06:10, 27 January 2008 (UTC)
[edit] null characters
just curious if string class accepts null characters. I would assume it does. —Preceding unsigned comment added by 66.102.196.17 (talk) 00:56, 28 February 2008 (UTC)
- I dug around in the gcc header files and found the following in basic_string.h: 1. String really contains _M_length + 1 characters: due to 21.3.4 must be kept null-terminated. But I am still not sure what that means fully. Guess I will have to test it. Kind of a lot to go through for a curiosity. I am starting to think it would have to be possible though, or how else would someone do binary file i/o. —Preceding unsigned comment added by 66.102.196.44 (talk) 03:03, 7 March 2008 (UTC)
- It appears to. It's not easy to add them, though, because
string foo = "asdf\0asdf";just sets foo to "asdf" because the null terminator means the string constructor never sees the second half of the string. But you can dostr.push_back('\0')and the length will increase and you can put non-null characters after the null terminator. —Ben FrantzDale (talk) 03:19, 8 March 2008 (UTC)
