Use Function and Member Function Templates

MATLAB^® supports C++ function and member function templates. The C++ interface generates a MATLAB function overload for each function template instantiation using a valid MATLAB name based on the C++ function name.

Display Help for Interface

Suppose that you have this C++ header file that defines a function template show. To run this example, follow the instructions in Build Interface for Overloaded Functions Example to generate a MATLAB interface named liboverload.

When you display help for liboverload, you see three calling syntaxes for show.

help clib.liboverload.show

  clib.liboverload.show    Representation of C++ function show.

  clib.liboverload.show(a)
    Input Arguments
      a              int32  

 clib.liboverload.show    Representation of C++ function show.

  clib.liboverload.show(a)
    Input Arguments
      a              double  

 clib.liboverload.show    Representation of C++ function show.

  clib.liboverload.show(a)
    Input Arguments
      a              read-only clib.liboverload.A  

Call show in MATLAB

If you type:

var = pi;
clib.liboverload.show(var)

then MATLAB chooses the signature with input type double.

Build Interface for Overloaded Functions Example

This C++ code defines a function template show and provides instantiations for types int, double, and const A.

class A{}; // User type
template<typename T> void show(T a) {}
template void show<int>(int);
template void show<double>(double);
template<> void show<const A &>(const A& a){}

To run the example, save this code in a header file named overload.hpp, then generate a MATLAB interface named liboverload following the instructions in Header-Only HPP File.

Library Artifacts	MATLAB Interface libname	MATLAB Help
Header file overload.hpp	clib.liboverload	>> help clib.liboverload

Unique Function Names

The C++ interface generates unique function names based on the signature types. To view the unique names for the show function, type:

help clib.liboverload

Classes contained in clib.liboverload:
A                              -  clib.liboverload.A    Representation of C++ class A.


Functions contained in clib.liboverload:
show                           -  clib.liboverload.show    Representation of C++ function show.

show_AConst__                  -  clib.liboverload.show    Representation of C++ function show.

show                           -  clib.liboverload.show    Representation of C++ function show.

show_double_                   -  clib.liboverload.show    Representation of C++ function show.

show                           -  clib.liboverload.show    Representation of C++ function show.

show_int_                      -  clib.liboverload.show    Representation of C++ function show.

To call the type-specific function for input of type double, type:

clib.liboverload.show_double_(var)

You can modify these names when publishing an interface to the library. For more information, see Customize Function Template Names.