Minisig is minimal, open source (LGPL), signals and slots library for C++.

It's not so powerfull like Boost.Signals or libsigc++ but it's very small (all library in one .h file), support up to 4 parameters and it's very easy to use.

Documentation is included in source file.

Example code:

void x(int i) { cout << i << endl; }
int y(long l) { cout << 2*l << endl; return 0; }
struct A { void a(int i) { std::cout << "A::a" << " " << i << endl; } };
void ignore_arg() { cout << "arg ignored" << endl; };
 
//...
 
minisig::signal<int> s;
s += x;
s += y;
A aa;
s.connect(aa, &A::a);
s.connect_ign1(ignore_arg);
s(1);	//call: x(1); y(1); aa.a(1); ignore_arg();

v0.4: minisig.h