1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
Adding converters for user defined types
========================================
It is possible to get luabind to handle user defined types like it does
the built in types by specializing ``luabind::default_converter<>``:
::
struct int_wrapper
{
int_wrapper(int value)
: value(value)
{}
int value;
};
namespace luabind
{
template <>
struct default_converter<X>
: native_converter_base<X>
{
static int compute_score(lua_State* L, int index)
{
return lua_type(L, index) == LUA_TNUMBER ? 0 : -1;
}
X from(lua_State* L, int index)
{
return X(lua_tonumber(L, index));
}
void to(lua_State* L, X const& x)
{
lua_pushnumber(L, x.value);
}
};
template <>
struct default_converter<X const&>
: default_converter<X>
{};
}
Note that ``default_converter<>`` is instantiated for the actual argument and
return types of the bound functions. In the above example, we add a
specialization for ``X const&`` that simply forwards to the ``X`` converter.
This lets us export functions which accept ``X`` by const reference.
``native_converter_base<>`` should be used as the base class for the
specialized converters. It simplifies the converter interface, and
provides a mean for backward compatibility since the underlying
interface is in flux.
|
