fastcast

Created: 2014-05-18 14:20
Updated: 2014-06-03 16:51
License: bsd-3-clause
c++

README.md

FASTCAST

Fastcast provides a fast alternative to dynamic_cast. Each class in the hierarchy has an integer identifier. This identifier is built to make instanceof operation very fast. Cross casts are supported.

Usage:

Fastcast is easy to use:

  1. include fastcast.hxx

  2. the root class (say A) must inherit from fastcast::fcast<A, uint64_t> (or an other integer type)

  3. each class in the hierarchy having children must typedef a fcast_hierarchy:

    // typedef for the root class
    typedef fastcast::hierarchy<fastcast::root, fastcast::children<B, C>> fcast_hierarchy;
    
    // typedef for a class other than root
    // The first template parameter gives the parent
    // and the second define the children
    typedef fastcast::hierarchy<A, fastcast::children<D>> fcast_hierarchy;
    
    // here there is no child
    typedef fastcast::hierarchy<D> fcast_hierarchy;
    
  4. Each constructor must set the identifier for the class (have a look at test/test.cpp):

    struct B : public A
    {
        typedef fastcast::hierarchy<A, fastcast::children<D>> fcast_hierarchy;
    
        B() { fastcast::fcast<A, uint32_t>::set_id<B>(); }
    };
    
  5. Cross casts are possible in using fastcast::parents (have a look at test/test_cross.cpp):

    struct G : public C, public E
    {
        typedef fastcast::hierarchy<fastcast::parents<C, E>, fastcast::children<H>> fcast_hierarchy;
    
        G()
            {
                FcastA::set_id<G>();
                FcastD::set_id<G>();
            }
    };
    
  6. the file test.cpp could be compiled in using:

    clang++ -Wall -std=c++11 -oout test/test.cpp -I. && ./out
    

    or

    g++ -Wall -std=c++11 -oout test/test.cpp -I. && ./out
    
Cookies help us deliver our services. By using our services, you agree to our use of cookies Learn more