coder.FunctionSignature

Examine this MATLAB function, which returns the product of the two input arguments. This function uses an arguments block to specify that the input arguments are scalar doubles.

function out = foo(a,b) %#codegen
arguments
    a (1,1) double
    b (1,1) double
end
out = a*b;
end

At the command line, create a FunctionSignature object for foo. You do not need to specify input arguments because the code generator can infer these arguments from the arguments block in the function body.

fsObj = coder.FunctionSignature("foo")

fsObj = 

  FunctionSignature with properties:

             Name: "foo"
             Args: "Auto"
          Nargout: []
    InterfaceName: ''

Generate a MEX function for foo. Specify fsObj as an entry-point function by using the -function option of the codegen command.

codegen -function fsObj

Code generation successful.

Test the MEX function. The MEX function produces the expected output.

foo_mex(3,4)

ans =

    12

Examine the value class Rectangle. The Rectangle class constructor defines a Rectangle object with a length and width specified by the properties Length and Width. The getArea method calculates the area of a Rectangle object. The isEqualArea method uses the getArea method to determine if two Rectangle objects have the same area.

classdef Rectangle
    properties
        Length 
        Width
    end
    methods
        function obj = Rectangle(length,width)
            obj.Length = length;
            obj.Width = width;
        end
        function area = getArea(obj)
            area = obj.Length*obj.Width;
        end
        function out = isEqualArea(obj1,obj2)
            out = isequal(getArea(obj1),getArea(obj2));
        end        
    end
end

Create a coder.ClassSignature object that represents the Rectangle class. When you create a coder.ClassSignature object by using the class name, the code generator infers the class properties from the constructor method.

classSig = coder.ClassSignature("Rectangle")

classSig = 

coder.ClassSignature
  1×1 Rectangle
      TypeName: "Rectangle"
    Properties: struct with no fields.
   Methods: dictionary (string --> cell) with no entries.

Create coder.FunctionSignature objects that represent methods of the Rectangle class. Specify an input argument that is an instance of the enclosing class by using the coder.ClassSignature object.

recFs = coder.FunctionSignature("Rectangle",{0,0});
gaFs = coder.FunctionSignature("getArea",{classSig});
ieaFs = coder.FunctionSignature("isEqualArea",{classSig,classSig});

Use the addMethod function to add the coder.FunctionSignature objects to the coder.ClassSignature object. Then, view the coder.ClassSignature object. MATLAB represents method arguments that are instances of the enclosing class by using the keyword this.

addMethod(classSig,recFs);
addMethod(classSig,gaFs);
addMethod(classSig,ieaFs)

ans = 

coder.ClassSignature
  1×1 Rectangle
      TypeName: "Rectangle"
    Properties: struct with no fields.
       Methods:
         Rectangle:
           Args: {1×1 double, 1×1 double}
         getArea:
           Args: {1×1 this}
         isEqualArea:
           Args: {1×1 this, 1×1 this}

Generate code for the Rectangle class by passing the coder.ClassSignature object to the codegen command with the -class option.

codegen -config:lib -lang:c++ -class classSig