Why doesn't std::list.push_back() work?

Question

C++ / C#

An object is created, push_back is made to std::list, but when iterating it is not [in std::list].
PS pastebin.com/9ygLzNVR (.hpp), pastebin.com/hV4bPUfH (.cpp)

Answer 1

The problem was this:
It should be:

inline const phys::World& world() const { return m_world; }
inline phys::World& world() { return m_world; }

And it was:

inline const phys::World world() const { return m_world; }
inline phys::World world() { return m_world; }

Answer 2

try iterating over the link
for (auto &b : m_bodies)