Implementing a high performance tensor library

Template methods have opened up a new way of building C++ libraries. These methods allow the libraries to combine the seemingly contradictory qualities of ease of use and uncompromising e ciency. However, libraries that use these methods are notoriously di cult to develop. This article examines the bene ts reaped and the di culties encountered in using these methods to create a friendly, high performance, tensor library. We nd that template methods mostly deliver on this promise, though requiring moderate compromises in either usability or e ciency.