Program Design Template: Fill & Download for Free

Some form of generic programming was envisioned for C++ from the earliest days. The very first papers on C++ (even before it had been named C++) from 1981 and 1982 show examples of parameterization by type. The obvious example illustrating the need was making the element type of a container (e.g., a vector) a parameter. So generic programming was there from day 1.However, I got the details all wrong. I used macros and thought that macros would do for generic programming. Until the end of the 1980s C++ implementations were shipped with a <generic.h> with supporting macros. That approach didn't scale, so I started to design templates after 1986.Alex Stepanov gave generic programming its modern form and wrote the STL. From 1994 or so his ideas have (deservedly) dominated thoughts about generic programming in C++ and he has crucially influenced the work on concepts (now available in GCC 6.1). Alex had been in Bell Labs earlier and we discussed how to support generic programming.As usual, some details and discussion can be found in D&E and my HOPL papers (e.g., see Stroustrup: C++).

They do, this is a well-known optimization that is very helpful for badly-designed template-heavy C++ code (well-designed template libraries avoid code duplication programmatically)Microsoft was the first to roll this out, I believe, and called it “ICF” (Identical COMDAT Folding) - it is enabled by default in release builds: -OPT (Optimizations)The link above also points out the problem with this, to quoteBecause /OPT:ICF can cause the same address to be assigned to different functions or read-only data members (const variables compiled by using /Gy), it can break a program that depends on unique addresses for functions or read-only data membersGNU has at least two levels of ICF (here “Identical Code Folding”): one done at gcc level with the option -fipa-icf (introduced in 5.x Link time and inter-procedural optimization improvements in GCC 5 ) and another level done by the gold linker with the option —icf=all (if you’re not using gold linker, what are you doing here in 2017?)The gold linker even has a way around the issue pointed out above, see option --icf=safe and the paper that introduced it https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/36912.pdf

Popular OO design patterns,Singleton Pattern: restricts the instantiation of a class to one objectTemplate Pattern: used to set up the outline or skeleton of an algorithm and lets subclass redefine certain steps of an algorithm without letting them to change the algorithm's structureFactory Pattern: creational design pattern to create object through a common interface without exposing the instantiation logicReactor Pattern: widely used in concurrent programming model, demultiplexes and dispatches service requests that are delivered concurrently to an application from one or more clients