c++ - terminology or design pattern name -

i reading source code in there class definition follows:

template<typename t> class c {     ...     t * func() {         const_cast<c *>(this)->somefunc();         ...     } }; 

i unable understand philosophy or purpose of syntax. , application of such code? know formal terminology/definition or design pattern same.

edit:

somefunc() implemented follows:

void somefunc() {     anotherfunc(*this); } 

and anotherfunc() is:

template<typename t> inline void anotherfunc(c<t> & a) {     throw std::runtime_error(std::string("blah blah blah")                              + typeid(t).name()); } 

then within code there classes like:

class f {     func_1();     func_2();     func_3(); } 

c instantiated this:

c<f> inst; 

then functions within f accessed inst->func_1();.

if 1 aiming redirect api use existing api, without forcing client change code.

if provide more context about

• somefunc() declaration.
• any class hierarchy.

to identify real need.