build fail on arm32

[welees]

When I build with arm-linux-gnueabi-gcc, the compiler report

http/server/HttpHandler.cpp:241:65: error: invalid use of incomplete type ‘class std::future<void>’
         hv::async(std::bind(handler->async_handler, req, writer));
                                                                 ^
In file included from cpputil/hthreadpool.h:16:0,
                 from cpputil/hasync.h:5,
                 from http/server/HttpHandler.cpp:8:
/usr/arm-linux-gnueabi/include/c++/5/future:115:11: note: declaration of ‘class std::future<void>’
     class future;
           ^
In file included from http/server/HttpHandler.cpp:8:0:
cpputil/hasync.h: In instantiation of ‘std::future<decltype (fn(hv::async::args ...))> hv::async(Fn&&, Args&& ...) [with Fn = std::_Bind<std::function<void(const std::shared_ptr<HttpRequest>&, const std::shared_ptr<hv::HttpResponseWriter>&)>(std::shared_ptr<HttpRequest>, std::shared_ptr<hv::HttpResponseWriter>)>; Args = {}; decltype (fn(hv::async::args ...)) = void]’:
http/server/HttpHandler.cpp:241:65:   required from here
cpputil/hasync.h:25:6: error: return type ‘class std::future<void>’ is incomplete
 auto async(Fn&& fn, Args&&... args) -> std::future<decltype(fn(args...))> {
      ^
cpputil/hasync.h:26:98: error: invalid use of incomplete type ‘class std::future<void>’
     return GlobalThreadPool::instance()->commit(std::forward<Fn>(fn), std::forward<Args>(args)...);

```                                                                                                  ^

[ithewei]

What is the gcc version? It must be at least gcc 4.8 and support full c++11.

[welees]

5.4

Target: arm-linux-gnueabi
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-armel-cross/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-armel-cross --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-armel-cross --with-arch-directory=arm --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libgcj --enable-objc-gc --enable-multiarch --enable-multilib --disable-sjlj-exceptions --with-arch=armv5t --with-float=soft --disable-werror --enable-multilib --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabi --program-prefix=arm-linux-gnueabi- --includedir=/usr/arm-linux-gnueabi/include
Thread model: posix
gcc version 5.4.0 20160609 (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9)

[ithewei]

It seems that your compiler does not support std::future. Can you write a simple std::future test program to test it?