Qt Creator: no member named 'ranges' in namespace 'std'

[slawtul]

Hi guys

I have 'visual' problem in Qt Creator. Qt Creator marks std::ranges with above error message however I can build and run program. I use gcc version 10.1.1 20200507 (Red Hat 10.1.1-1) (GCC)
Do you know how to fix it?

Regards
Slawek

[jsulm]

@slawtul Did you include <ranges>?

Please post your code as text not screen shots.

[slawtul]

@jsulm

Hi,
yes, I have <ranges> in Playground.h file - I forgot to move it to Playground.cpp but even when I move it to cpp file there is still error message.
I opened this project under Clion IDE and it's ok.

#ifndef PLAYGROUND_H
#define PLAYGROUND_H

#include <iostream>
#include <ranges>

class Playground {
public:
  void showABCWithRange();
};

#endif // PLAYGROUND_H

[slawtul]

Proof:

#include <iostream>
#include <ranges>

#include "Playground.h"

void Playground::showABCWithRange() {
  std::cout << std::ranges::size("ABC") << "\n";
}

Process Error: 5
Output:
/home/slawtul/sources/Cpp_tools/Playground_lib/Playground.cpp:7:21: error: no member named 'ranges' in namespace 'std'
  std::cout << std::ranges::size("ABC") << "\n";
               ~~~~~^
1 error generated.
11:28:42: Error: Failed to analyze 1 files.

[J.Hilk]

@slawtul ranges requires c++20 did you enable that ? And does your compiler support it?

[JonB]

@J-Hilk
I'm sure that is indeed the issue, though it's slightly surprising that OP is successfully using #include <ranges> without that complaining.... Must be that the file does exist but does nothing inside it if C++ < 20 ?

[slawtul]

Hi
I mentioned in the first post that program builds and runs - both from terminal and from Qt Creator.

Below few lines from CMakeList.txt:

cmake_minimum_required(VERSION 3.15)
project(Cpp_tools)

set(CMAKE_CXX_STANDARD 20)
add_compile_options(-Wall -Wextra -Wpedantic -Werror)

Do I need to enable 'something else' in Qt Creator to get ride of this error message?

From my konsole:

[slawtul@localhost ~]$ gcc -v
gcc version 10.1.1 20200507 (Red Hat 10.1.1-1) (GCC) 

[slawtul@localhost ~]$ clang -v
clang version 10.0.0 (Fedora 10.0.0-2.fc32)

Thanks!
Slawek

[J.Hilk]

@slawtul well, than its a clang code model issue,
not all too surprising, IIRC c++20 support for clang code model is not jet finished

[slawtul]

@J-Hilk

Ok, now I understand and found Clang Code Model you are reffering to...
So 'under the hood' Qt Creator checks my code with Clang 10.0.0 version which does not have <ranges> implemented.

Thanks!