This technique is often used for security-sensitive projects involving binary protection, obfuscation etc.

Program Obfuscation via ABI Debiasing (pdf) - https://www.google.com/goto?url=CAESYgHuR6pNsi8_4x_I2WBy7lmf...

PS: James Coplien in his excellent Advanced C++ Programming Styles and Idioms shows many techniques one of which is actually replacing vtable entries at runtime to mimic features from more dynamical runtime languages (eg. Smalltalk).