[backport#15308] Piecewise construct to avoid invalid construction
Summary:
In CMainSignals::RegisterWithMempoolSignals running under Ubuntu 14.04
(QT 5.2), absent piecewise construction this fails to create the pair
because the argument is a connection, which is converted into a
non-copyable scoped_connection.
validationinterface.cpp:80:186: required from here
/usr/include/boost/signals2/connection.hpp:234:7: error: ‘boost::signals2::scoped_connection::scoped_connection(const boost::signals2::scoped_connection&)’ is private
scoped_connection(const scoped_connection &other);
^
In file included from /usr/include/c++/4.8/utility:70:0,
from /usr/include/c++/4.8/algorithm:60,
from ./prevector.h:13,
from ./script/script.h:10,
from ./primitives/transaction.h:11,
from ./validationinterface.h:9,
from validationinterface.cpp:6:
/usr/include/c++/4.8/bits/stl_pair.h:134:45: error: within this context
: first(std::forward<_U1>(__x)), second(__y) { }https://travis-ci.org/bitcoin/bitcoin/jobs/473689141#L2172
This is a partial backport of Core PR15308
Test Plan:
ninja check
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Subscribers: Fabien
Differential Revision: https://reviews.bitcoinabc.org/D6148