The simplest data to register within a namespace is a variable. Variables can be registered with the addVariable (char const*, T*, bool isWritable) function. This function is templated, meaning that any type of variable can be added using the function. The first argument to this function is the name that Lua will call the variable, the second is a pointer to the C++ variable. The third argument is optional. When set to true (the default value), the variable can be read from and written to, and when set to false, the variable becomes read-only.
The following code demonstrates how to register a variable with Lua Bridge:
int bar;
getGlobalNamespace(L)
.beginNamespace("foo")
.addVariable("bar", &bar)
.endNamespace()