What is it?

Static(ly-typed) queued connections for Qt signals.

Why?

• arguments can be any copyable types, i.e.:
  • no type registration needed (Q_DECLARE_METATYPE, qRegisterMetaType() etc.);
  • no default constructors required;
• slightly faster (no per-argument memory allocations);
• argument types in signal declarations do not need to be namespace-qualified.

Why not?

• receivers must not change their thread affinity while any squco-connections any active, undefined behaviour otherwise;
• error messages on incompatible parameters may be worse than from QObject::connect();

Requirements

• C++14;
• Qt5 (tested on Qt 5.9.1)

Usage

Similar to the standard 4-argument QObject::connect():

To connect:

squco::connectSlot(f, &From::signalX, t, &To::slotY);

squco::connectFunctor(f, &From::signalX, t, [t, otherParam]{ t->abc(5, otherParam); });

To disconnect:

auto conn = squco::connectSlot(...);
...
QObject::disconnect(conn);

Naturally, squco always assumes Qt::QueuedConnection.

Not yet tested in production. Reports welcome.

More examples

See unit tests in test.cpp.

License

MIT