JSConversions: A general system of converting between native objects and their JavaScript representations

implemented by MarkT; documented by janwas.

note: "native" denotes C++ types/values, as opposed to JS objects that wrap them.

ToNative/ToScript

Overview:
Converts C++ JSObject-derived class pointers to and from JSObject*.
Syntax:
template T* ToNative( JSContext* cx, JSObject* obj );
template T* ToNative( jsval v );
template JSObject* ToScript( T* Native );
Example: CDamageType* dmg = ToNative( argv[0] );
Parameters:
ToNative: optionally either JSContext* and JSObject*, or jsval (useful for converting argvi)
ToScript: C++ class pointer
Returns:
The C++ class pointer resp. JS object pointer.
Notes:

Overview:
Converts C++ built-in types or classes (if the requisite specialization exists) to and from jsval.
Syntax:
template bool ToPrimitive( JSContext* cx, jsval v, T& Storage );
template bool ToPrimitive( JSContext* cx, jsval v, T*& Storage );
template inline T ToPrimitive( JSContext* cx, jsval v );
template inline T ToPrimitive( jsval v );
template jsval ToJSVal( T& Native );
template jsval ToJSVal( T*& Native );
template jsval ToJSVal( const T& Native );
Example: ToPrimitive( cx, argv[0], gain);
Parameters:
ToPrimitive: the script context (if desired); value to convert and destination.
ToScript: the C++ value to convert.
Returns:
bool to indicate success resp. resulting JS value.
Notes:
The T*& calls automatically dereference pointers-to-objects.