Compilation problem in Ubuntu 14.04 with g++-4.9

[redrattus]

I use the wangle version 0.13.0 and the folly version 0.57.0!

[ 20%] Building CXX object CMakeFiles/wangle.dir/acceptor/Acceptor.cpp.o
In file included from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/Acceptor.h:14:0,
from /home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:10:
/home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ConnectionManager.h: In instantiation of ‘static wangle::ConnectionManager::UniquePtr wangle::ConnectionManager::makeUnique(Args&& ...) [with Args = {folly::EventBase_&, const std::chrono::duration<long int, std::ratio<1l, 1000l> >&, wangle::Acceptor_}; wangle::ConnectionManager::UniquePtr = std::unique_ptr<wangle::ConnectionManager, folly::DelayedDestruction::Destructor>]’:
/home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:87:54: required from here
/home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ConnectionManager.h:64:34: error: no matching function for call to ‘make_unique(folly::EventBase_&, const std::chrono::duration<long int, std::ratio<1l, 1000l> >&, wangle::Acceptor_)’
std::forward(args)...);
^
/home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ConnectionManager.h:64:34: note: candidates are:
In file included from /usr/local/include/folly/io/Cursor.h:31:0,
from /usr/local/include/folly/io/async/AsyncSSLSocket.h:32,
from /home/junhosuh/workspace/wangle/wangle/../wangle/ssl/SSLUtil.h:14,
from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ServerSocketConfig.h:15,
from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/Acceptor.h:12,
from /home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:10:
/usr/local/include/folly/Memory.h:48:1: note: template<class T, class ... Args> typename std::enable_if<(! std::is_array< >::value), std::unique_ptr >::type folly::make_unique(Args&& ...)
make_unique(Args&&... args) {
^
/usr/local/include/folly/Memory.h:48:1: note: template argument deduction/substitution failed:
In file included from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/Acceptor.h:14:0,
from /home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:10:
/home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ConnectionManager.h:64:34: note: cannot convert ‘std::forwardfolly::EventBase*&((* & args#0))’ (type ‘folly::EventBase_’) to type ‘folly::DelayedDestruction::Destructor&&’
std::forward(args)...);
^
In file included from /usr/local/include/folly/io/Cursor.h:31:0,
from /usr/local/include/folly/io/async/AsyncSSLSocket.h:32,
from /home/junhosuh/workspace/wangle/wangle/../wangle/ssl/SSLUtil.h:14,
from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ServerSocketConfig.h:15,
from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/Acceptor.h:12,
from /home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:10:
/usr/local/include/folly/Memory.h:55:1: note: template typename std::enable_if<std::is_array< >::value, std::unique_ptr >::type folly::make_unique(size_t)
make_unique(const size_t n) {
^
/usr/local/include/folly/Memory.h:55:1: note: template argument deduction/substitution failed:
In file included from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/Acceptor.h:14:0,
from /home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:10:
/home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ConnectionManager.h:64:34: error: wrong number of template arguments (2, should be 1)
std::forward(args)...);
^
In file included from /usr/local/include/folly/io/Cursor.h:31:0,
from /usr/local/include/folly/io/async/AsyncSSLSocket.h:32,
from /home/junhosuh/workspace/wangle/wangle/../wangle/ssl/SSLUtil.h:14,
from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ServerSocketConfig.h:15,
from /home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/Acceptor.h:12,
from /home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:10:
/usr/local/include/folly/Memory.h:63:1: note: template<class T, class ... Args> typename std::enable_if<(std::extent<Tp>::value != 0), std::unique_ptr >::type folly::make_unique(Args&& ...)
make_unique(Args&&...) = delete;
^
/usr/local/include/folly/Memory.h:63:1: note: template argument deduction/substitution failed:
/usr/local/include/folly/Memory.h: In substitution of ‘template<class T, class ... Args> typename std::enable_if<(std::extent<Tp>::value != 0), std::unique_ptr >::type folly::make_unique(Args&& ...) [with T = wangle::ConnectionManager; Args = {folly::DelayedDestruction::Destructor}]’:
/home/junhosuh/workspace/wangle/wangle/../wangle/acceptor/ConnectionManager.h:64:34: required from ‘static wangle::ConnectionManager::UniquePtr wangle::ConnectionManager::makeUnique(Args&& ...) [with Args = {folly::EventBase&, const std::chrono::duration<long int, std::ratio<1l, 1000l> >&, wangle::Acceptor}; wangle::ConnectionManager::UniquePtr = std::unique_ptr<wangle::ConnectionManager, folly::DelayedDestruction::Destructor>]’
/home/junhosuh/workspace/wangle/wangle/acceptor/Acceptor.cpp:87:54: required from here
/usr/local/include/folly/Memory.h:63:1: error: no type named ‘type’ in ‘struct std::enable_if<false, std::unique_ptr<wangle::ConnectionManager, std::default_deletewangle::ConnectionManager > >’
make[2]: *_* [CMakeFiles/wangle.dir/acceptor/Acceptor.cpp.o] Error 1
make[1]: *** [CMakeFiles/wangle.dir/all] Error 2
make: *** [all] Error 2

[tomsercu]

I have the same issue installing wangle on a RHEL6 system, using gcc 4.9. I have folly @ cef5789.
This occurs both when compiling with the default -std=c++0x (giving the error just like above),
and with -std=c++14 in CMakeLists.txt it will indicate it is trying to use make_unique from gcc-4.9.2_rhel6/include/c++/4.9.2/bits/unique_ptr.h, however the error remains the same.

[tomsercu]

No answer from JunhoSuh or the developers.
The error comes from the fact that old versions of folly had a non-standard make_unique that takes 2 template arguments. This is now removed, presumable so that make_unique follows the std::make_unique in c++14.
You can work around it like this (in acceptor/ConnectionManager.h)

  template<typename... Args>
  static UniquePtr makeUnique(Args&&... args) {
    //return folly::make_unique<ConnectionManager, Destructor>(
    //  std::forward<Args>(args)...);
    return std::unique_ptr<ConnectionManager, Destructor>(
      new ConnectionManager(std::forward<Args>(args)...));
  }

[fugalh]

This is due to repositories being out of sync (folly and wangle).

On Wed, Oct 21, 2015 at 3:48 PM Tom Sercu notifications@github.com wrote:

No answer from JunhoSuh or the developers.
The error comes from the fact that old versions of folly had a
non-standard make_unique that takes 2 template arguments. This is now
removed, presumable so that make_unique follows the std::make_unique in
c++14.
You can work around it like this (in acceptor/ConnectionManager.h)

template<typename... Args>
static UniquePtr makeUnique(Args&&... args) {
//return folly::make_unique<ConnectionManager, Destructor>(
// std::forward(args)...);
return std::unique_ptr<ConnectionManager, Destructor>(
new ConnectionManager(std::forward(args)...));
}

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