+
f is compatible if for the given set of argument types Arg1, Arg2, ..., ArgN and a return type ResultType, the appropriate following function is well-formed:
+
+ // if ResultType is not void
+ ResultType foo(Arg1 arg1, Arg2 arg2, ..., ArgN argN)
+ {
+ return f(arg1, arg2, ..., argN);
+ }
+
+ // if ResultType is void
+ ResultType foo(Arg1 arg1, Arg2 arg2, ..., ArgN argN)
+ {
+ f(arg1, arg2, ..., argN);
+ }
+
+ A special provision is made for pointers to member functions. Though they are not function objects, Boost.Function will adapt them internally to function objects. This requires that a pointer to member function of the form R (X::*mf)(Arg1, Arg2, ..., ArgN) cv-quals be adapted to a function object with the following function call operator overloads:
+
+ R operator()(cv-quals X& x, Arg1 arg1, Arg2 arg2, ..., ArgN argN) const
+ {
+ return x.*mf(arg1, arg2, ..., argN);
+ }
+
+ R operator()(cv-quals X* x, Arg1 arg1, Arg2 arg2, ..., ArgN argN) const
+ {
+ return x->*mf(arg1, arg2, ..., argN);
+ }
+
+ template<typename P>
+ R operator()(cv-quals P& x, Arg1 arg1, Arg2 arg2, ..., ArgN argN) const
+ {
+ return (*x).*mf(arg1, arg2, ..., argN);
+ }
+
+function_base Class function_base is the common base class for all Boost.Function objects. Objects of type function_base may not be created directly.
@@ -114,10 +153,18 @@
!empty()safe_bool equivalent of !empty()safe_bool type can be used in contexts where a bool is expected (e.g., an if condition); however, implicit conversions (e.g., to int) that can occur with bool are not allowed, eliminating some sources of user error.
+safe_bool equivalent of empty()safe_bool conversion
functionN template<typename F> functionN(const F& g, const Mixin& = Mixin());
g is a compatible function object.g is a compatible function object.Mixin subobject from the given mixin.f targets a copy of g if g is nonempty, or f.empty() if g is empty.g is a reference-to-const because it is a portable, efficient, and concise way to accept any function object or function pointer. In the case of a function pointer, the type of g is reference-to-const pointer-to-function. template<typename F> functionN& operator=(const F& g);
g is a compatible function object.g is a compatible function object.f targets a copy of g if g is nonempty, or f.empty() if g is empty.*this.g is a reference-to-const because it is a portable, efficient, and concise way to accept any function object or function pointer. In the case of a function pointer, the type of g is reference-to-const pointer-to-function.