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Standard Template Library Programmer's Guide
(document number: 007-3426-004 / published: 1999-05-21) table of contents | additional info | download
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Adaptable Generator


Category: functors	Component type: concept

Description

An Adaptable Generator is a Generator with a nested typedef that defines its result type. [1] This nested typedef makes it possible to use function object adaptors.

Refinement of

Generator

Associated types

Result type F::result_type The type returned when the Generator is called

Notation

`F`	A type that is a model of Adaptable Generator

Definitions

Valid expressions

None, except for those defined by Generator

Expression semantics

Complexity guarantees

Invariants

Models

The STL does not include any types that are models of Adaptable Generator. An example of a user-defined Adaptable Generator is as follows.

struct counter
{
  typedef int result_type;

  counter() : n(0) {}
  result_type operator()() { return n++; }

  result_type n;
};

Notes

[1] Note the implication of this: a function pointer T (*f)() is a Generator, but not an Adaptable Generator: the expression f::result_type is nonsensical.