#include <iostream>
#include <string>
int main()
{
std::string test = "45";
int myint = stoi(test);
std::cout << myint << '\n';
}
I tried this code on my computer which is running MinGW GCC 4.7.2. It gives me this error:
What am I doing wrong, I got this from cppreference. Its the exact same code. And its a different error from the one described here.
It seems your MinGW needs a patch: Enabling string conversion functions in MinGW
This patch enables the following list of C++11 functions and templates
in the std namespace:
stoi, stol, stoul, stoll, stof, stod, stold,
to_string, to_wstring
In above link, there is a .zip file, download it and
Copy wchar.h and stdio.h from the include directory in the zip file
to the following directory (overwrite): C:\mingw\include (replace
C:\mingw\ with the appropriate directory)
Copy os_defines.h to the following directory (overwrite):
C:\mingw\lib\gcc\mingw32\4.7.0\include\c++\mingw32\bits (replace
C:\mingw\ with the appropriate directory) (replace 4.7.0 with the
correct version number)
Another solution is to use MinGW-w64, which works correctly out of the box. This is a fork of MinGW that can produce both 32-bit and 64-bit builds.
Related
I just updated my MacBook Pro to macOS Catalina 10.15, and tried to compile and run a C++ command line program, but I had a problem which didn’t exist on previous versions;
This is simply the code:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello, World!\n";
return 0;
}
The code compiles and outputs the expected, but still the Xcode says:
fatal error: 'iostream' file not found
I tried changing the Build Settings/C++ Standard Library to libstdc++, but a warning says:
warning: include path for stdlibc++ headers not found; pass '-stdlib=libc++' on the command line to use the libc++ standard library instead
And the same iostream error still exists.
I'm compiling from the command line, and none of the answers listed here (or elsewhere) worked for me.
What does seem to work (so far) is to add the following to .profile or whatever script your terminal uses to start up: (zsh, csh, bash, etc.)
export C_INCLUDE_PATH=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/include
export CPLUS_INCLUDE_PATH=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/include
You will probably have to change MacOSX10.15.sdk whenever you upgrade your operating system.
C_INCLUDE_PATH and CPLUS_INCLUDE_PATH are options for the clang toolchain rather than MacOS environment, so hopefully this solution will work long-term, unlike xcode-select --install (which won't fix the include directories on an upgrade) or ln -s ... /usr/include (which is now forbidden by System Integrity Protection).
I had the same problem and used the following youtube video to fix it.
https://www.youtube.com/watch?v=hrPm7tWC-BI&feature=youtu.be
or you can follow this path. Make sure to include the quotation marks
Project - Build Settings - Search Paths - Headers Search Paths, and add the following path:
"/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/"
So, I restarted my laptop and everything seems to be fine right now, thanks for those who tried to help.
libstdc++ is not OK for Xcode Build & Compile time,
libstdc++ is OK for iPhone Run Time
From answer recommended by #Alan Birtles
libstdc++ Support was removed from the iOS 12.0 Simulator runtime, but
it remains in the iOS 12.0 (device) runtime for binary compatibility
with shipping apps.
I encountered this when declaration in .hpp file.
#include <iostream>
#include <string>
OK with
#ifdef __cplusplus
#include <iostream>
#include <string>
// usage code
#endif
I tried a fresh Catalina install with Xcode. I copied and pasted your code into "test.cpp" and then ran:
clang++ test.cpp
in the same directory as the "test.cpp" file from Terminal. The result was an "a.out" file which when run:
./a.out
output the required "Hello, World!" result. Hopefully that is of some use (as a point of reference).
Most probably this is weird, but when I got this error that stoi wasn't declared in this scope, I smiled because I am familiar with this error and it's solution.
I checked this option have g++ follow the c++11 ISO c++ language standard [-std=c++11] in compiler settings of Code Blocks (16.01, with MinGW) and tried recompiling it, but surprisingly it didn't work and the same error persisted. I tried re-installing CodeBlocks but that didn't work.
Also, I tried with windows power shell and command prompt with g++ math_handler.cpp -std=c++11 but got the same error.
What am I doing wrong?
the code is here:
#include<string>
using namespace std;
int main()
{
string body="456";
int i=stoi(body);
}
Note:
I tried with -std=c++0x and g++ too.
the same problem with to_string() function.
gcc version 4.9.2 (tdm -1)
Okay, I found that it is a known bug in MinGW bundled with CodeBlocks. I found the solution here.
Download mingw-to-string-gcc47.zip which contains three patched
header files. (Original patches: wchar.h, stdio.h, os_defines.h)
Copy wchar.h and stdio.h from the include directory in the zip file
to the following directory (overwrite): C:\mingw\include (replace
C:\mingw\ with the appropriate directory)
Copy os_defines.h to the following directory (overwrite):
C:\mingw\lib\gcc\mingw32\4.7.0\include\c++\mingw32\bits (replace
C:\mingw\ with the appropriate directory) (replace 4.7.0 with the
correct version number)
Did you include the required header file?
#include <string>
stoi is also in the std namespace so:
std::stoi()
or:
using namespace std;
#include <iostream>
#include <string>
int main()
{
std::string test = "45";
int myint = stoi(test);
std::cout << myint << '\n';
}
I tried this code on my computer which is running MinGW GCC 4.7.2. It gives me this error:
What am I doing wrong, I got this from cppreference. Its the exact same code. And its a different error from the one described here.
It seems your MinGW needs a patch: Enabling string conversion functions in MinGW
This patch enables the following list of C++11 functions and templates
in the std namespace:
stoi, stol, stoul, stoll, stof, stod, stold,
to_string, to_wstring
In above link, there is a .zip file, download it and
Copy wchar.h and stdio.h from the include directory in the zip file
to the following directory (overwrite): C:\mingw\include (replace
C:\mingw\ with the appropriate directory)
Copy os_defines.h to the following directory (overwrite):
C:\mingw\lib\gcc\mingw32\4.7.0\include\c++\mingw32\bits (replace
C:\mingw\ with the appropriate directory) (replace 4.7.0 with the
correct version number)
Another solution is to use MinGW-w64, which works correctly out of the box. This is a fork of MinGW that can produce both 32-bit and 64-bit builds.
#include <iostream>
#include <string>
int main()
{
std::string test = "45";
int myint = stoi(test);
std::cout << myint << '\n';
}
I tried this code on my computer which is running MinGW GCC 4.7.2. It gives me this error:
What am I doing wrong, I got this from cppreference. Its the exact same code. And its a different error from the one described here.
It seems your MinGW needs a patch: Enabling string conversion functions in MinGW
This patch enables the following list of C++11 functions and templates
in the std namespace:
stoi, stol, stoul, stoll, stof, stod, stold,
to_string, to_wstring
In above link, there is a .zip file, download it and
Copy wchar.h and stdio.h from the include directory in the zip file
to the following directory (overwrite): C:\mingw\include (replace
C:\mingw\ with the appropriate directory)
Copy os_defines.h to the following directory (overwrite):
C:\mingw\lib\gcc\mingw32\4.7.0\include\c++\mingw32\bits (replace
C:\mingw\ with the appropriate directory) (replace 4.7.0 with the
correct version number)
Another solution is to use MinGW-w64, which works correctly out of the box. This is a fork of MinGW that can produce both 32-bit and 64-bit builds.
I downloaded Code::Blocks from here: http://www.codeblocks.org/downloads/26
I'm learning c programming. When I run the following program, I get error:
iostream: No such file or directory
error: syntax error before "namespace"
warning: type defaults to `int' in declaration of `std'
warning: data definition has no type or storage class
In function `main':
error: `cout' undeclared (first use in this function)
error: (Each undeclared identifier is reported only once
error: for each function it appears in.)
error: `cin' undeclared (first use in this function)
I'm running the following program:
#include <iostream>
using namespace std;
int main()
{
int x;
x = 0;
do {
// "Hello, world!" is printed at least one time
// even though the condition is false
cout<<"Hello, world!\n";
} while ( x != 0 );
cin.get();
}
I tried Dev-C++, I get the same error.
How to fix this?
Is this in a file like "program.c" or "program.cpp"? If it's a .c file, then your compiler may be interpreting it as C, and not C++. This could easily cause such an error. It's possible to "force" the compiler to treat either such extension as the other, but by default, .c files are for C, and .cpp files are compiled as C++.
It's either this, or somehow your default "include" directories for the standard library are not set up right, but I don't know how you'd fix that, as that'd be compiler/environment dependent.
I also had that problem when trying to run my first program in Code::Blocks. My file was saved with '.c' extension as 'test.c' and when I saved it as 'test.cpp', it worked fine.
It is also worth mentioning that I had to restart Code::Blocks before new 'test.cpp' file was compiled successfully.
While saving your source code before compiling just save the name with extension ".cpp". You wont get the error..
I got the same problem.
Change #include < iostream.h >
to #incude < iostream >
Consequently, in your program, change every keyword related to iostream, such as cin cout and endl to std::cout, std::cin and std::endl
That'll do the trick
Use <iostream> instead of <iostream.h>
and add std:: before cout, cin etc
Use std::cout << "Welcome";
instead of cout << "Welcome";
Save the file with .cpp extension
you have missing iostream.h file in you mingw directory folder placed inside codeblocks/devc++. what you have to do is just download the file from link given below and replace with your previous mingw folder in codeblocks/devc++.
http://www.4shared.com/rar/owp-D0Km/mingw.html
I found the problem was cause by having a previous version of cgg and cpp in a Perl installation. The Perl structure did not have the correct library files. When I added C:\MinGW\bin and C:\MinGW\MSYS\1.0\bin to the path, I added them at the end so it picked up the Perl install first. I moved the path variable entries to the beginning and reopened my cmd window and it now works because it finds the MinGW version first.
Type path to see your path environment varialble. Mine now looks like:
C:\MinGW>path
PATH=C:\MinGW\bin;C:\MinGW\MSYS\1.0\bin;C:\Perl\site\bin;C:\Perl\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\Program Files\WIDCOMM\BluetoothSoftware\;
Apparently you want to create a c++ file. But you allowed your computer to auto provide the file extension C/C++. When it does that it automatically provides a file extension of ".c". Which is not corect. You want ".cpp".
Solution: Rename your file with a ".cpp" extension, or else explicitly state your extension when saving new files by putting ".cpp" (without quotes of course) after your intended file name; i.e. specify your file extension.
I tried in Dev-C++ . Instead of iostream.h use iostream also write the using namespace std;
#include<iostream>
using namespace std;
int main()
{
cout<<"Hello World\n";
return 0;
}
you written your program in C++ code use c code then your program run correctly
in first line use it
#include <Io stream.h>
main ()
{
in ending line use it
system (pause");
You are trying to make a C game right? If you are your code is C++ not C. So if you are trying to make a C game than you should change your code. This might help.
Just put "Using namespace std;" before main() to define the scope of identifiers you are using. This will handle your problem easily.
Try including iostream.h instead of iostream.