# Integration
Luwra does not provide a standalone version of Lua nor does it capsule its features. This means that
all functions and classes operate on
[lua_State](http://www.lua.org/manual/5.3/manual.html#lua_State) (or the alias
[State](/reference/namespaceluwra.html#a2c037b44385367826eb4e931b5b8197d)). Doing this allows you to
integrate Luwra however you like.

# Stack Interaction
Although Luwra provides a variety of features, its main concern is efficient and safe interaction
with the Lua stack.

A fundamental aspect of this is the abstract template [Value](/reference/structluwra_1_1Value.html).
Every type which can be pushed onto or read from the stack has a specialization of it.
Useful implementations are provides out of the box:

C++ type               | Pushable | Readable | Lua type
-----------------------|----------|----------|----------------------------
bool                   | yes      | yes      | boolean
signed char            | yes      | yes      | number (integer since 5.3)
signed short           | yes      | yes      | number (integer since 5.3)
signed int             | yes      | yes      | number (integer since 5.3)
signed long int        | yes      | yes      | number (integer since 5.3)
signed long long int   | yes      | yes      | number (integer since 5.3)
unsigned char          | yes      | yes      | number (integer since 5.3)
unsigned short         | yes      | yes      | number (integer since 5.3)
unsigned int           | yes      | yes      | number (integer since 5.3)
unsigned long int      | yes      | yes      | number (integer since 5.3)
unsigned long long int | yes      | yes      | number (integer since 5.3)
float                  | yes      | yes      | number
double                 | yes      | yes      | number
long double            | yes      | yes      | number
const char*            | yes      | yes      | string
std::string            | yes      | yes      | string
std::nullptr_t         | yes      | yes      | nil
std::tuple<T>    | yes      | no       | *depends on the tuple contents*
[lua_CFunction](http://www.lua.org/manual/5.3/manual.html#lua_CFunction) | yes | no | function
[NativeFunction<R(A...)>](/reference/structluwra_1_1Value_3_01NativeFunction_3_01R_07A_8_8_8_08_4_01_4.html) | no | yes | function
[FieldVector](/reference/structluwra_1_1Value_3_01FieldVector_01_4.html) | yes | no | table

**Note:** Some numeric types have a different size than their matching Lua type - they will be
truncated during push or read operations.

# From C++ to Lua
When pushing values onto the stack you can either use
[Value<T>::push](/reference/structluwra_1_1Value.html#aa376d68285606c206562b822e8187384) or the more
convenient [push](/reference/namespaceluwra.html#ae8e7eab11fc2cf3f258ffd81571066fa).
See these examples:

```c++
// Push an integer
luwra::push(lua, 1338);

// Push a number
luwra::push(lua, 13.37);

// Push a boolean
luwra::push(lua, false);

// Push a string
luwra::push(lua, "Hello World");
```