Composition of two or more functors

Collaboration diagram for Composition of two or more functors:

Functions
template<class UnaryOp , class Functor >
auto	dg::compose (UnaryOp f, Functor g)
	Create Composition functor \( f(g(x_0,x_1,...)) \).
template<class UnaryOp , typename... Functors>
auto	dg::compose (UnaryOp f0, Functors... fs)
	Create Composition funtor of an arbitrary number of functions \( f_0(f_1(f_2( ... f_s(x_0, x_1, ...)))\).

Detailed Description

Function Documentation

compose() [1/2]

template<class UnaryOp , class Functor >

auto dg::compose	(	UnaryOp	f,
		Functor	g )

Create Composition functor \( f(g(x_0,x_1,...)) \).

dg::Grid2d grid2d( -1., 1., -1., 1., 3, 40, 40);
//Mark everything above 2 with 1s and below with 0s
dg::HVec fg = dg::evaluate( dg::compose( dg::Heaviside( 2.), dg::Gaussian( 0., 0., 2., 2., 4.)), grid2d);

Template Parameters

UnaryOp	Model of Unary Function taking the return type of g return_type_f f(return_type_g)
Functor	Inner functor, takes an arbitrary number of parameters and returns one return_type_g g(value_type0,value_type1,...)

Parameters

f	outer functor
g	inner functor

Attention

only works for host functions. The rationale is that this function is intended to work with lambda functions and previously nvcc did not support lambdas. If a version for device functions is ever needed it can be provided.

Returns

a function object that forwards all parameters to g and returns the return value of f, which is \( f(g(x_0,x_1,...)) \)

compose() [2/2]

template<class UnaryOp , typename... Functors>

auto dg::compose	(	UnaryOp	f0,
		Functors...	fs )

Create Composition funtor of an arbitrary number of functions \( f_0(f_1(f_2( ... f_s(x_0, x_1, ...)))\).

Template Parameters

UnaryOp	Model of Unary Function taking the return type of f_1 return_type_f0 f0(return_type_f1)
Fs	UnaryOps except the innermost functor, which takes an arbitrary number of parameters and returns one return_type_fs f_s(value_type0,value_type1,...)