Explore the design and evolution of Mach7, a pattern matching library for C++, in this comprehensive conference talk from C++Now 2014. Delve into pattern matching concepts, semantics, and applications across various programming languages. Examine design ideals, criteria, and goals behind the Mach7 library. Learn about structural decomposition, nested matching, relational matching, and pattern combinators. Discover how Mach7 implements algebraic decomposition and handles complex data structures like red-black trees. Gain insights into pattern-subject interactions, expression templates, and the library's core concepts. Understand the implementation of primitive patterns, structural decomposition bindings, and constructor patterns using macros and meta-programming techniques.