Binding pointer to pointer type doesn't compile

[deadlocklogic]

Consider

struct Test {};

and the binding code

Test1** test;
lua["Test"] = test;

Error messages:

/opt/compiler-explorer/libs/sol2/trunk/include/sol/stack_core.hpp:1416:28: error: no matching function for call to object of type 'std::less<void>'
/opt/compiler-explorer/libs/sol2/trunk/include/sol/stack_core.hpp:1416:28: error: no matching function for call to object of type 'std::less_equal<void>'
/opt/compiler-explorer/libs/sol2/trunk/include/sol/stack_core.hpp:1416:28: error: no matching function for call to object of type 'std::equal_to<void>'

@ThePhD Any ideas on how to pass raw pointer to pointer?