Is it possible to add support for custom types?

[CJCombrink]

Is your feature request related to a problem? Please describe.

Is it possible to add TOML support for custom types, example:

struct Point {
    int32_t x = 10;
    int32_t y = 20;
}

Which would probably look like the following in TOML

[custom_point]
x = 10
y = 20

Describe the solution you'd like

I would like to use it as follow:

const Point my_point = tbl["custom_point"].value<Point>();

Additional context

I am not yet using the library but working thought the API docs I don't see any mention of such options.