function result is meant to be transient, and therefore should not be regularly storeable by the user... but there is no way to make a "and you can't have anything but a temporary to this" type, as far as I can tell.
sol::object had a few reference leaks in the way it retrieved values: it now does it properly without leaving the stack at +1 item
sol::stack was drastically cleaned up, with the following key change:
* sol::stack::push now returns an integer of the number of things its pushed (usually 1, but can be more) (Thanks, @PrincessNyanara!)
* sol::stack::call now calls functions flexibly, and getting is done more reliably
* due to the innovation of stack::call and using absolute indices, we no longer have to use reverse_call style programming to deal with lua
* sol::reference::get_type is now const-correct
* sol::state and sol::table now have a cleaned up `get` implementation since it is no longer held back by the ugliness of VC++'s incapability to handle templates
* the name `sol::userdata` now belongs to a type that actually encapsualtes a void* with a pusher/getter than gets a userdata void* value (TODO: give it a template to make it static_cast to that type on get?)
* lightuserdata_t -> light_userdata, upvalue_t -> upvalue as type names (mostly details)
* pushers for various types were updated to return integers
now are usable as functions for userdata.
allows free functions and lambdas to provide useful operations, like operator+*-/
and other things which may not be implemented as class members.
this triggered overhaul of set_function/pusher<function_t>::push(...)
both state and table reflect changes to userdata structure to make it easier to use
tests updated to account for overload resolution
some function-related traits added to make use easier -- cleaned up archaic typenames in function_types.hpp
Account for std::reference_wrapper for objects -- sol now uses copy-by-default (value-semantics) for all functors
updated tests to reflect this
c++ semantics dictate that it's accessed by index, but the tests seem to want to indicate that it should be accessed like a hashmap (or just using basic lua table semantics)
i have no idea how to make this incompatibility work in the new system...
i will ask repo master if he knows anything
i want to use an is_function trait to differentiate classes when they get pushed
problem i feel that is_function may capture things not necessarily intended to be function objects
right now it is only qualified by pusher<function_t>
if change is necessary, then it becomes pusher<T, EnableIf<IsFunction<T>>>
a lua upvalue can be lightuserdata, userdata, or anything else that can have its address taken (it's immediately popped of the stack and carted around with function call)
a lightuserdata can only be a pointer (void*)
a regular userdata can be anything, but is stored as void* because of "anything" semantics and C heritage of lua
upvalues deserve to use the `lua_upvalueindex(n)` macro: lightuserdata/userdata does not (must not) go through this process
get turned into getter<T>, matches pusher<T> and uses same semantics as std::allocator and other things used throughout the codebase
-----
userdata has its traits defined outside in new file of userdata to prevent errors when trying to use those typetraits in places before userdata.hpp gets included
userdata was changed to support returning itself via pointers or references.
rework of stack changes semantics based on T&, T*, and T&& (the last one tries to create a new userdata and move in data)
solves problems maybe presented in https://github.com/Rapptz/sol/issues/25
-----
container.hpp is attempt at solving original problem before going on wild tangent with userdata, stack, and get
is going to attempt to use userdata to allow transporation of containers losslessly, perhaps without copying need
-----
found out trying to return a std::function does not work -- not sure what do exactly?
perhaps should push c closure as last thing, but right now it is tied to a key value (code comes from table.hpp and set_function)
will just have to think over how stack arranges itself and learn what to do
by forward-declaring the std::function overload in `stack`, it is able to find the right function to use.
All tests are passing
the ninja file has been tweaked to make it easier to invoke a g++ build on windows
But! I left it on the `sol::function` type, because it's necessary to discard returns. The .call is still there, though, just incase you need it. <3
reverse_indices_builder is also there, to make sure we can push and pop without the lua api taking our types and breaking them for the std::tuple returns.
All is at it should be~
It'll be up to @Rapptz's to make further changes to make sure GCC compiles, but the core of the functionality is there and my work is essentially done.
Class bindings are up next, but really I don't want to even touch those. :c
