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I'm using Visual Studio Code to compile C++ programs and it works for most C++ programs as it compiles it using g++ command. However, I am facing difficulty in compiling c++11 programs using it.
When I try compiling C++11 programs, the compiler command g++ tries to compile it using default C++98 Standard and this results in errors.
I am aware that using g++ -std=c++11, we can compile C++11 programs using g++ and it works fine when I use it in my cmd as:
g++ -std=c++11 some_program.cpp
I wish I could tweak some setting in Visual Studio Code and change the compiler command from g++ to g++ -std=c++11 so that I could compile programs by just hitting the run code button. However, I'm not able to find one. Please help me out if there are alternate ways to get my program compiled.
Currently, I'm getting errors as:
some_program.cpp: In function 'int main()':
some_program.cpp:12:33: error: in C++98 'A' must be initialized by constructor, not by '{...}'
vector A = { 11,2,3,14 };
The snippets are correct and have been tested with online compilers using C++11. Here, it is trying to compile using C++98 as seen in the error.
Go to Settings > User Settings
In here, search for Run Code Configuration:
Under this menu, find:
"code-runner.executorMap"
Edit this Setting by adding it to User Setting as below for C++11 support:
"code-runner.executorMap":{
"cpp": "cd $dir && g++ -std=c++11 $fileName -o $fileNameWithoutExt && $dir$fileNameWithoutExt",
},
OR
Edit this Setting by adding it to User Setting as below for C++17 support:
"code-runner.executorMap":{
"cpp": "cd $dir && g++ -std=c++17 $fileName -o $fileNameWithoutExt && $dir$fileNameWithoutExt",
},
Hope this helps !
Related
I want to use c++11/14 features like range-based loops, but get a warning while doing g++ program.cpp. If done with compiler flag g++ -std=c++11 program.cpp the warning goes away. Is there a way to use c++11/14 by default on the g++ command (i.e without passing compiler flag every time).
Please explain to someone with limited knowledge of compilers and only need the c++11/14 features for competitive programming problems (even if it's a bad idea in general, maybe due to backward compatibility?)
Short Answer: Update your g++
According to g++ documentation
The default, if no C++ language dialect options are given, is -std=gnu++17.
You are probably using an older version of g++. You can check it using by running g++ --version in your terminal. If you are using Linux, you can also extract your default c++ standard from g++ manual with the command man g++ | col -b | grep -B 1 -e '-std.* default' in your terminal.
If you do not want to update your g++, you can also set a command alias by putting something like alias g+++='g++ -std=c++14' in your .bashrc
If you're using a gcc version > 4.9.3 use this command: g++ -std=c++14 program.cpp
If you're using an older version than that use g++ -std=c++1y program.cpp
Note: Consider adding the -Wall flag before program.cpp in your command to get warnings, they help you way more than you'd think!
Tip: If you're a starting developer and don't want too steep of a learning curve, try using an IDE before going full command-line.
EDIT: If you want a command to be "the default" you can add something like alias mycc='g++ -std=c++14 -Wall' in your .bashrc or .bash_profile file (see this link), then you'll be able to use mycc program.cpp
I'm using atom to practice C++ (I'm very new). I just learned to initialize variables like the following:
#include <iostream>
using namespace std;
int main() {
int myInt {};
return 0;
}
When I build and run the previous code in codelite I receive no errors. However, if I compile my atom file dailyPractice10.cpp using my MacBook terminal (zsh) I get the following error:
dailyPractice10.cpp:7:12: error: expected ';' at end of declaration
int myInt {};
^
;
1 error generated.
I'm using the following command to compile it on terminal:
g++ -o dailyPractice10 dailyPractice10.cpp (compiles)
./dailyPractice10 (runs program)
Does anyone have any feedback why this code runs in codelite but doesn't compile in terminal?
Because this feature is added from c++11.
if you will like to try below command.it will work.
$ g++ -std=c++0x -o dailyPractice10 dailyPractice10.cpp
The key to fixing this issue is to set the C++11 (or above) standards while building your code.
In the console tab of the IDE, the following output is generated before the error. Notice that no standard is being defined while building the code:
make all
Building file: ../1.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"1.d" -MT"1.o" -o "1.o" "../1.cpp"
We need to add the --std=c++1x flag to the g++ command. The following solution is for the ones using the Eclipse IDE and the MacOSX C++ compiler:
Right click on the project from the "Project Explorer".
Go to Properties > C/C++ Build > Settings.
Under the "Tool Settings" tab, find "GCC C++ Compiler" > "Miscellaneous"
In the "Other Flags" text box, edit the text such that it looks like:
-std=c++17 -c -fmessage-length=0
If you intend to use any other c++ standard, replace "c++17" with the standard of your choice ( eg. c++20).
Apply Changes.
Run Clean, and the Build again.
you should try this to compile the Code
g++ -std=c++20 -o dailyPractice10 dailyPractice10.cpp
I use coderunner installed in vscode to run my c++ code, but it just can't run in c++11 style so it always appears c++11 errors and warnings, how can i do to make it available to c++ 11 ?
For enabling C++11 on coderunner(vscode) please check if the setting has it enabled.
Go to
Settings > User Settings
In here, search for
Run Code Configuration:
In the menu find: "code-runner.executorMap"
Then edit the setting by adding it to User Setting as below for C++11 support:
"cpp": "cd $dir && g++ -std=c++11 $fileName -o $fileNameWithoutExt && $dir$fileNameWithoutExt"
Hope this helps !
For more help check this
So I'm following the tutorials on this page:
http://www.cplusplus.com/doc/tutorial/control/
But I'm having trouble doing a range/based for loop. I found this page:
GNU GCC compiler updatingThe answer there says I should open "Project" and "Properties". But when I try that, the "Properties" option is grayed out with no explanation:
http://imageshack.com/a/img571/4371/xd1x.png
So.. how can I activate range/based for loops?
Pass -std=c++11 flag to the compiler. Certainly GCC should be fresh enough (>=4.7) to support all these modern standards. For CodeBlocks 13.12: Settings -> Compiler -> Tab "Compiler Flags" -> Option "Have g++ follow the C++11 ISO C++ [-std=c++11]"
The above given solution of using -std=c++11 didn't work for me.
This is the target and version detail of my compiler.
gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)
Target: x86_64-linux-gnu
When I tried, this is what happened.
$ g++ -std=c++11 program.cpp
cc1plus: error: unrecognized command line option ‘-std=c++11’
This solved the problem for me.
$ g++ -std=c++0x program.cpp
In Dev-Cpp 5.11 Simply you can click on Tools>Compiler Options>Settings>Code Generation>(and in last option)Language standard(-std) select from dropdown (ISO C++ 11).
If you faced this error in Code::Blocks, this might help you -
Click on Settings -> Compiler -> Compiler Settings -> Compiler Flags
Under the "General" section, check [✓] the box beside :
Have g++ follow the C++11 ISO C++ language standard [-std=c++11]
Both of these:
g++ -std=c++11 -o test_executable test_source.cpp
g++ -std=c++0x -o program program.cpp
worked for me.
Only thing to do after compiling is to execute the test_executable (in the first case) as ./test_executables or program (in the second case) as ./program.
Using the above solution
g++ -std=c++0x program.cpp
works. However, the command needs to be modified slightly in order to run the program with the common command:
./program
I used
g++ -std=c++0x -o program program.cpp
and all worked perfectly.
If you are using QT5.5, you can achieve it by adding following lines in your .pro file.
CONFIG += c++11
The best solution is doing this, in Dev C++:
Go to the "Tools" Option
Select "Compiler Options"
Click "Settings"
Click "Code Generation"
Go to "Choose Language" and select "ISO C++11"
Then your problem is resolved.
in first time, if you have Dev-C++
C:\Program Files (x86)\Dev-Cpp\MinGW64\bin, you must add this route to the path
then use the next command in cmd.
g++ -std=c++11 -o outprogram code_source.cpp
this command in your project directory.
I'm trying to change the settings of g++ from the Code::Blocks IDE. I went to the Settings tab, clicked Compiler... and checked various options for the compiler to use, like
Enable all warnings (-Wall)
Have g++ follow the C++11 ISO C++ language standard (-std=c++11)
......
These are just two of many others; when I compile on the command line, here is what comes up:
g++ -o example example.cpp
# warning: initializer lists only available with -std=c++11 ...
Notice how there's no warning either - I have an unused variable in my program. It only works if I give the options manually:
g++ -Wall -std=c++11 -o example example.cpp
Do you think I might have done something wrong when setting up the compiler? Why aren't the options taking affect?
Invoking the compiler from the ide is completely independent from doing it in a command line shell. There's no reason for the setting and usage of one to have any effect on the other.