I'm kinda new to C++ and making .h files, so I was wondering if you could try out my library

[west oasis]

I'm making a hex identifier for a password embedder program that i'm making, and i was wondering if you could review the library i'm making for the hex identifier

[fierce steppe]

Compiler Output

<source>:3:10: fatal error: string: No such file or directory
    3 | #include <string>
      |          ^~~~~~~~
compilation terminated.
Build failed

SirBluberry#9057 | c | x86-64 gcc 12.2 | godbolt.org

[steady prairie]

using namespace std in a header isn't a good idea

[west oasis]

then what should i use?

should i use the traditional std:: method?

[steady prairie]

yes definitely

[west oasis]

okay, thanks

here it is now

[steady prairie]

very cool 👍

[west oasis]

thank you

[steady prairie]

do you know why this is?

[west oasis]

i wonder

[steady prairie]

actually hold on let me test something

[west oasis]

heres the new one

[steady prairie]

so

if i include your header, i would also have using namespace std; in my code now

#include "hzHEXstd.h"
#include <algorithm>

int main() {
    min(1, 3); // available without std:: prefix even though it's after the `using namespace std;` thing
}

and then naming conflicts

at least thats as far as i know

[lunar stream]

@west oasis Are these just ascii codes in hex?

I wouldn't make named string constants for these

[west oasis]

these are ascii to hex, yes

i was kinda worrying about putting them to strings

[lunar stream]

std::string ascii_to_hex(char c) {
    std::stringstream ss;
    ss<<std::hex<<int(c);
    return std::move(ss.str());
}
```should do it

[west oasis]

all of that?

so what does it do?

[lunar stream]

ascii_to_hex

[west oasis]

so it converts ascii symbols to hexadecimal?

[west oasis]

thanks guys
!close

!close

hmm...

[foggy geode]

Doesn't this return std::move prevent RVO?

or can rvo not kickin because youre using the .str method

https://en.cppreference.com/w/cpp/io/basic_stringstream/str

yea it does

std::stringstream::str returns a new string

[lunar stream]

@orchid nest has a good explanation for this

but I forget what it was

[foggy geode]

return std move rvo stuff is hard

ill wait for him to explain it

[orchid nest]

Should be return std::move(ss).str();

This will cause it to choose the rvalue overload, which means that str() will move out of ss's underlying buffer rather than copying

equivalently, doing ```cpp
std::string ascii_to_hex(char c) {
return (std::ostringstream{} << std::hex << (int)c).str();
}

[lunar stream]

Oh, right 🙂

[frank fern]

but isnt this only since C++20?

is there anything similar pre C++20?

because i mostly use C++17

[orchid nest]

yes, there's no way of doing this pre-C++20

But simultaneously, doing this has no harm in C++17 either, and you get free perf improvements if you move to C++20