Language Binding: C++

The language binding layer takes the interface description given as a binding DSEL and creates the corresponding meta-object binding in C++. This is both generating the C++ code, through template instantiations. And creating an instance of the meta-object binding for other languages to use.

Interface DSEL

A domain specific embeded language (DSEL) describes and defines the exposed C++ interfaces.

namespace_, module

Define a namespace scope for definitions.

def

Declare a binding of a static or global.

class_

Declare a binding class.

class_.def

Declare either a value or function member of the class.

class_.def_readwrite

A readable and writable property.

class_.def_readonly

A readable, only, property.

class_.property

A custom read and/or write property.

class_.enum_

An enumeration within the class.

class_.scope

Begin declarations within the class scope.

constructor

Define a constructor for the class.

self, const_self, other

Reference to arguments of our own class.

tostring

Printable representation of the instance.

enum_

Scope level enumeration.

value

Value in an enumeration.

operators

“+”, “-”, “*”, “/”, “==”, “<”, “<=”

Return value policies

• adopt – Binding language takes ownership of the result object instance.
• dependency – Extends the lifetime of arguments to the result lifetime.
• return_reference_to – Indicates that the result is one of the arguments.
• copy – Indicates that a result should be copied when returned.
• discard_result – Ignores the result, making the exposed function return void.

Parameter policies

• out_value – Defines arguments that will also be returned, either as part of the result or through a reference argument.
• pure_out_value – An out_value which is not exposed in the function binding.

Storage policies

For C++ the goal of the binding DSEL is to generate the primary meta-object binding that other languages will use to bind to.