I'm trying to use a couple of functions from the Boost Math library in some C++ code using the G++ compiler but I've been unsuccessful. This is on macOS.
I downloaded and extracted the Boost tar.gz from here and placed it into my source folder.
Within my C++ I've tried
#include "boost_1_63_0/boost/math/distributions/chi_squared.hpp" and
#include <boost_1_63_0/boost/math/distributions/chi_squared.hpp>.
The quotation version partially works but the chi_squared.hpp file includes fwd.hpp using the bracket (#include <...>) notation and that breaks my compilation with error In file included from main.cpp:9: ./boost_1_63_0/boost/math/distributions/chi_squared.hpp:12:10: fatal error: 'boost/math/distributions/fwd.hpp' file not found #include <boost/math/distributions/fwd.hpp>.
To compile I've used an assortment of commands, all unsuccessfully:
g++ -L /boost_1_63_0/boost/math/distributions main.cpp
g++ -I"/boost_1_63_0/boost/math/" main.cpp
g++ -I "/boost_1_63_0/boost/math/" main.cpp
g++ main.cpp -lboost_math
What is the correct include statement and G++ command that I need to use?
Resolved using
#include "/Users/[me]/[project_dir]/boost_1_63_0/boost/math/distributions/chi_squared.hpp"
and
g++ -I/Users/[me]/[project_dir]/boost_1_63_0/ main.cpp
Related
I am trying to use this C++ library (png++) on Windows, but I unable to compile any program when I use it. Example of Code I am using to test:
#include <png++/png.hpp>
#include <png.h>
int main(){
//anything
}
When I try to compile using g++ -I path/png++ main.cpp -o main, I get
fatal error: png++/png.hpp: No such file or directory
#include <png++/png.hpp>
I understand png++ depends on libpng, I tried adding it as an I- flag, i.e. compile using
g++ -I path/png++ -I path/libpng main.cpp -o main, but it doesn't resolve the issue, png.h is found by the compiler but not png++/png.hpp.
I hope someone will be able to help.
Thanks!
I am trying to compile a c++ code with a third party library using g++ as a compiler.
My main.cpp needs to include the header file core.hpp while the core.hpp needs to include cvdef.h whereas cvdef.h need to include interface.h.
The paths for these three headers in the include statements are as follows:
#include "opencv2/core.hpp"
#include "opencv2/core/cvdef.h"
#include "opencv2/core/hal/interface.h"
See file structure in image below.
When I compile my main.cpp it finds the core.hpp. The core.hpp, however, cannot seems to find cvdef.h as it is looking within the 'core'-folder for the 'opencv2'-folder (which is a level below).
Without changing the paths in the include statement, how would I go about this?
My current compile statement using g++ under Windows is:
g++ main.cpp -o main
It seems that OpenCV2 wants to look for the header files in standard locations.
You can add to the list of standard locations by using the -I (upper-case i) option, specifying the path to add.
In your case you should be able to do it with
g++ main.cpp -o main -Iopencv2/core
I’m a newbie to C++ and Linux. There is this code I’m playing with that requires me to install the HElib (Homomorphic encryption library and other libraries - GMP, NTL) which I did. I want to compile the code (main.cpp) that has a header file (FHE.h) in HElib. My problem is how can I link FHE.h (in HElib folder) and main.cpp (in another folder) together so that I can compile them. I have tried some commands
g++ -I/Home/HElib/src/FHE.h main.cpp -o main
Error message
main.cpp:1:17: fatal error: FHE.h: No such file or directory
compilation terminated.
Another command line
g++ -I/Home/HElib/Src/FHE.h -I/Home/SimpleFHESum-master/SimpleFHESum-master/main.cpp -o main]
Error Message
g++: fatal error: no input files
compilation terminated.
What's wrong and how can I fix this?
The -I flag adds the following directory to the include path of the compiler. This enables you to write e.g. #include "FHE.h" even though that file is not located in the same folder as the source file you're trying to compile.
Have you tried just removing the 'FHE.h' part from your -I directive?
g++ -I/Home/HElib/src ...
Environment
Ubuntu 16.04
G++ 5.3.1
I have a header file with the following intended to include a different .h file depending on platform:
#ifdef _WIN32
#include "curses.h"
#else
#include <ncurses.h>
#endif
This works fine in windows but in Ubuntu I get errors about the curses.h file:
In file included from /usr/include/unctrl.h:54:0,
from /usr/include/curses.h:1694,
from headers/command_window.h:8,
from command_window.cpp:1:
headers/curses.h:900:19: error: macro "clear" passed 1 arguments, but takes just 0
int clear(void);
This when compiling with:
g++ -g -lncurses -std=c++11 -Iheaders -c -o command_window.o command_window.cpp
Why is headers/curses.h, which is the windows specific file for PDCurses being involved here at all?
/usr/include/unctrl.h contains this line:
#include <curses.h>
And since you've told the compiler to look in your headers/ folder for header files with the -Iheaders flag , the compiler picks up curses.h in that folder.
So you need to drop the -Iheaders flag (and e.g. use #include "headers/header_name.h") or you need to rename your headers/curses.h to not collide with /usr/include/curses.h
In your version of g++, the -I option is not the correct way to add application-specific header files (those that shouldn't be found by #include in system headers) to the search path (this change surprised me as well).
Instead, you should use -iquote headers.
See this answer: How to tell g++ compiler where to search for include files? and this official documentation
How can I query the default include path of clang/clang++? I am trying to use a custom built clang compiler (the one that supports OpenMP), but it doesn't seem to find the STL libraries:
/usr/local/bin/clang++ hello.cpp
hello.cpp:1:10: fatal error: 'iostream' file not found
#include <iostream>
^
1 error generated.
By using an IDE, back-tracking the #include iostream, and finally using the -isystem option I got the simple helloworld application to compile in OSX 10.9:
/usr/local/bin/clang++ -isystem /Library/Developer/CommandLineTools/usr/lib/c++/v1 hello.cpp
Thanks for your help!
You are looking for option -v. Compiling with clang++ -c file.cc -v will print among other things:
#include "..." search starts here:
#include <...> search starts here:
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9
etc.
If you run
clang++ -### hello.cpp
It will display the commands used to compile that particular file, including the default include paths, library search paths, targets etc.