I'm getting an error with #include <thread>
The error is -
In file included from /usr/include/c++/4.8/thread:35:0,
from main.cpp:35:
/usr/include/c++/4.8/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO C++ 2011 standard. This support is currently experimental, and must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
But I'm compiling with c++11 like so...
g++ main.cpp -o main -std=c++11
Also compiling through NetBeans with c++11 selected.
gcc version 4.8.5 (SUSE Linux)
g++ version 4.8.5 is fairly old with only partial thread support. See https://gcc.gnu.org/onlinedocs/gcc-4.8.5/libstdc++/manual/manual/status.html#status.iso.2011
Try updating your gcc suite to the latest version for your distro and you should be good.
Related
I have a c++ project using boost 1.77.0 library. The compiler is g++ 4.8.5, and as I know it supports the c++11 standard. The following command is used to compile the project:
g++ -std=c++11 main.cpp Logger.cpp MOCMesh.cpp Mesh.cpp CFDMesh.cpp Solver.cpp -o main -I../tools -I/usr/code/include -I. -L/usr/code/lib -lgmp -lphtread -lmpfr
However, I got errors told c++ standard unsatisfied:
/usr/code/include/boost/multiprecision/detail/number_base.hpp:36:2: error: #error "This library now requires a C++11 or later compiler - this message was generated as a result of BOOST_NO_CXX11_HDR_TYPE_TRAITS being set"
#error "This library now requires a C++11 or later compiler - this message was generated as a result of BOOST_NO_CXX11_HDR_TYPE_TRAITS being set"
...
For some reasons, I cannot update the GNU compilers to latest or higher version, so is there anyone knows how to solve this issue?
Use an older version of boost from that time period
When compiling my cpp file on linux with the following line:
$ g++ -o blabla blabla.cpp
I get the following message on stdout:
In file included from
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/array:35,
from blabla.cpp:5: /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../
include/c++/4.4.7/c++0x_warning.h:31:2:
error: #error This file requires compiler and library support for the
upcoming ISO C++ standard, C++0x. This support is currently
experimental, and must be enabled with the -std=c++0x or -std=gnu++0x
compiler options.
The script does #includes the <vector> and <array> libraries, so I don't know why it fails.
What causes this error?
Above error are coming because you are using the latest feature of C++, and you default version is older than required.
Flags (or compiler options) are nothing but ordinary command line arguments passed to the compiler executable.
g++ -std=c++0x -o blabla blabla.cpp
I have an issue when compiling a simple Hello file with an empty function taking initializer_list argument when using both -stdlib=libstdc++ and -std=c++11
If I use only -std=c++11 (which means compiling with libc++)
then the file compiles and prints Hello!
If I comment function_test and I use both -std=c++11 and -stdlib=libstdc++
then the file compiles and prints Hello!
If I keep the function function_test and I use both -std=c++11 and -stdlib=libstdc++
then I get the following error:
$ g++ -stdlib=libstdc++ -std=c++11 -o test test.cpp
test.cpp:1:10: fatal error: 'initializer_list' file not found
#include <initializer_list>
^
1 error generated.
Here is my file
#include <initializer_list>
#include <iostream>
using namespace std;
void function_test(initializer_list<int> something){}
int main(int argc, char * argv[])
{
cout << "Hello!" << endl;
function_test({0});
return 0;
}
Here is my apple clang version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr
--with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 7.0.2 (clang-700.1.81)
Target: x86_64-apple-darwin15.3.0
Thread model: posix
--with-gxx-include-dir=/usr/include/c++/4.2.1
^^^^^^^
Notice the "4.2". Your libstdc++ is way to old for C++11. Upgrade it to some 5.x version for full C++11 support.
I found out that upgrading to a newer version of libstdc++ is just not possible with apple-llvm(clang). So using some features of C++11 with libstdc++ is not possible. The reason is this one:
Mainline libstdc++ has switched to GPL3, a license which the
developers of libc++ cannot use. libstdc++ 4.2 (the last GPL2 version)
could be independently extended to support C++11, but this would be a
fork of the codebase (which is often seen as worse for a project than
starting a new independent one). Another problem with libstdc++ is
that it is tightly integrated with G++ development, tending to be tied
fairly closely to the matching version of G++.
source:
http://libcxx.llvm.org/docs/
Thanks to all the answers/comments that helped me reach the answer.
This is the first time I use clang. What I notices is that any error from clang referencing the std library looks like this:
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/ostream:245:7:
^^^ ^^^ ^^^
So it looks like clang links — or at least includes — the gcc libraries.
The command I used: clang++ -c -Wall -Wextra -Werror -g test.cpp -o test.o. (The program had a intentional error just to prove this).
How is this possible? What can I do to make clang use its own libraries (but not break gcc)?
Additional information:
I am on a Ubuntu 14.04 machine.
clang++ --version
Ubuntu clang version 3.5-1ubuntu1 (trunk) (based on LLVM 3.5)
Target: x86_64-pc-linux-gnu
Thread model: posix
g++ --version
g++ (Ubuntu 4.8.2-19ubuntu1) 4.8.2
Copyright (C) 2013 Free Software Foundation, Inc.
I had previously installed several versions (at the same time, used them with update-alternatives) of gcc with apt-get. Right now I have only 4.8 (I have uninstalled the others). Could I have messed up something then? I have never installed clang (I guess it is default with Ubuntu).
Just to clarify: the correct programs compile and run in clang++.
Further tests: I know that gcc didn’t implement yet types like is_trivially_constructible and move operations on iostream in their standard c++11 library (https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html) and that clang has full c++11 conforming library so I tested those compiling with clang and I got the corresponding gcc errors, which only confirms that clang is using gcc libraries.
A very basic program
#include <iostream>
using namespace std;
int main() {
cout << "Yada Yada" << endl;
return 0;
}
gives this error when compiling with -std=c++1y in clang++:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/iostream:39:
...
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/cstdio:120:11: error: no member named 'gets' in the global namespace
using ::gets;
~~^
So right now I can’t compile anything with c++1y in clang.
You need to install libc++ and make clang use it with -stdlib=libc++
I had similar issue: GCC (g++) already was installed on my LinuxMint (Ubuntu base) so when compile with clang, was getting an " error: no member named 'gets' in the global namespace using ::gets ".
resolved by installing libc++-dev (sudo apt-get install libc++-dev) and compiling with -stdlib++ (clang++ -g -std=c++1y -stdlib=libc++ helloworld.cpp -o helloworld)
Your real problem is that you're using C++14 (c++1y was the informal name used to refer to it when it wasn't yet fully formed), with a C++ library belonging to GCC 4.8. GCC 4.8 has complete C++11 support, but hardly even started on C++14 features.
This is caused by C++14 removing std::gets, and the GNU C library anticipating on that by not defining gets in the global namespace while the C++ library has not yet caught up and is trying to make it available in the std namespace.
The proper way to solve this does not require using libc++, just to use a C++ library with C++14 support. GLIBCXX 4.9 (aka libstdc++) already suffices.
i have some problem with my boost library. i m using freebsd and installed my boost using ports. Boost version is : 1.45 and i use g++47 as compiler. Also i have never defined BOOST DISABLE THREADS at there : /usr/local/include/boost/config/user.hpp .Also exactly my error is :
/usr/local/include/boost/config/requires_threads.hpp:29:4: error: #error "Threading support unavaliable: it has been explicitly disabled with BOOST_DISABLE_THREADS"
explicitly but where ?? And my compile command;
g++47 -O3 -Wall -std=c++0x -I. -Iinclude -I../include -I/usr/local/include -c -o Application.o src/Application.cpp
Thanks
The experimental GCC version 4.7 disables Boost.Threads. See: https://svn.boost.org/trac/boost/ticket/6165
Edit: It should be noted that as of the release version of GCC 4.7, and Boost higher than 1.48 (Boost_1_48_0 is still not working), threads works again.
See the ticket 6165 mentioned above by Joachim:
To define 'threads' support, GCC <= 4.6 defines _GLIBCXX__PTHREADSwhereas GCC >= 4.7 defines _GLIBCXX_HAS_GTHREADS. So, in order to compile older Boosts using any GCC more recent than 4.6 you need the patch libstdcpp3.hpp.patch enclosed in that ticket.
Another problem that could also prevent Boost on working with modern compiler is ticket 6940 (TIME_UTC has a special meanhing in C11, therefore Boost >= 1.50 use TIME_UTC_ instead)