You're right. Type punning via pointer cast, e.g.

  int i = ...
  float f = *(float*) &i;

is not fine (violates strict aliasing). Type punning via union, e.g.

  union { int i; float f; } u;
  u.i = ...
  float f = u.f;

is, though (but only in C).

Just use memcpy :-)