I don't think that actually breaks things. A typedef isn't purely syntactic substitution like a macro. If we have typedef float *floatp; then the follow

I don't think that actually breaks things. A typedef isn't purely syntactic substitution like a macro. If we have typedef float *floatp; then the following compiles: float x, y; floatp xp = &x, yp = &y; while the following does not: float x, y; float* xp = &x, yp = &y; You have defined a new type (which happens to be equivalent to an old type - note that we don't get nominal type-checking from typedefs); the above logic still holds.