libsigc++ 2.2.10
Classes | Modules
Lambdas

libsigc++ ships with basic lambda functionality and the sigc::group adaptor, which uses lambdas to transform a functor's parameter list. More...

Classes

struct  sigc::lambda_base
 A hint to the compiler. More...
struct  sigc::lambda< T_type >
 Lambda type. More...

Modules

 group()
 

sigc::group() alters an arbitrary functor by rebuilding its arguments from one or more lambda expressions.



Detailed Description

libsigc++ ships with basic lambda functionality and the sigc::group adaptor, which uses lambdas to transform a functor's parameter list.

The lambda selectors sigc::_1, sigc::_2, ..., sigc::_9 are used to select the first, second, ..., nineth argument from a list.

Examples:
 std::cout << sigc::_1(10,20,30); // returns 10
 std::cout << sigc::_2(10,20,30); // returns 20
 ...

Operators are defined so that, for example, lambda selectors can be used as placeholders in arithmetic expressions.

Examples:
 std::cout << (sigc::_1 + 5)(3); // returns (3 + 5)
 std::cout << (sigc::_1 * sigc::_2)(7,10); // returns (7 * 10)