In EiffelLanguage, a readout/printout/listing of a class language which has implementation details (method bodies, mainly) and private features excluded. Method signatures (including pre/post-conditions) and other interface details for exported features are the only things provided.

Note that in Eiffel; these are provided by the toolset.

C++ has a similar concept, in that for many classes the implementation details are not given in the class definition (usually located in a .h file) and instead are given in a corresponding implementation (.cc, .cpp, .cxx, whatever) file. Difference in C++ is that the programmer must maintain both the interface definition and the implementation separately; they can get out of sync (though any good environment will catch this quickly).

'''no not really. Unless you go to the trouble of using the pImpl idiom lots of implementation detail is visible in a C++ class declaration ("the .h file").  NickKeighley'''