Im not an expert in any kind of compile time computing methods but i know that template metaprogramming provides such a functionality. Pdfsam basic portable, a free, open source, multiplatform software designed to split, merge, extract pages, mix and rotate pdf files packed as a portable app so you can do your pdf split and merge on the go. Mos 4465a is an advanced financial ac modern advanced accounting in canada, 8th edition, mcgraw. Access to each resource is mediated by a perresource mutex.
The output of these templates include compiletime constants, data structures, and complete functions. Monkey patching is an object oriented programming technique that allows developers to. Most people insist on trying to metaprogram from inside their favorite language. Efficient algorithms for membership testing, random access, and retrieval by key. Ever since generic programming was introduced to c programmers have discovered myriad template tricks for manipulating programs as they are compiled effectively eliminating the barrier between program and metaprogram. While i consider myself falling rather in the camp of the aficionados, ive met a lot more people that dont have a strong interest for it, or that even find it downright disgusting, than tmp enthusiasts. Net and vbscript using pdf extractor sdk check this article also to learn how to split pdf into multiple files weve listed different code snippet below. Note that the second parameter is an int, not a type. Recently, very few research threads on underpinning. The chapter presents further examples for this usage as well. Metaprogramming with templates yes, the code checks whether the number is a prime number template struct isprime2. This could be done to improve your programs runtime performance in exchange for slower compile times or. A way around this is to do metaprogramming from outside the language, using program transformation tools. It provides the foundation youll need to use the template metaprogramming effectively in your own work.
It creates a new document and then adds a clone of the pages from each input document. Template metaprogramming is an emerging new direction of gen erative. That book certainly isnt what id call light reading, but it does introduce some valuable techniques. In the following code sample you can see how you can easily merge pdf files into one. Things like template, which look really weird but behave in an even more bizarre way. C program to merge two files and store their contents in another file. Sep 09, 20 what weve done now is program a little function or subroutine that is evaluated compiletime, using tmp. Check this article also to learn how to split pdf into multiple files. Another advantage is that you can look at a template class and immediately see if it is a template metaprogram or an ordinary template class. Reflection support by means of template metaprogramming. This post starts a series of articles following the contrived and tortuous path down insanity lane. Metaprogramming with templates yes, the code checks whether the number is a prime number template aug 02, 2016 examples of metaprogramming.
Template metaprogramming is an emerging new direction of gen erative programming. Some small examples of template metaprogramming in action. I have a struct with a template that expects nontype variadic pack of type char, defined trivially as. Caveat i decided to do this talk after getting thoroughly lost on the recent talk on sfinae.
C program to merge two files programming simplified. Yes, its a weird name, but its a powerful and dangerous tool. Dec 20, 2016 having large or multiple pdf files, both are difficult to manage. The simple idea is to pass data type as a parameter so that we dont. In general, macros are frowned upon in this role and templates are preferred, although they are not as generic.
On the other hand it might result in code bloat and performance decrease. Grab it directly from the iterator c deref, parent, visitcount grab the first value from the subtree contained in the iterator c deref. The files to be merged are opened in read mode and the file that contains contents of both the files is opened in write mode. This code is helpful if youd read a tutorial or two and would like to see tmp put to work on some canned problems. It has all the same features as pdfsam basic, plus, it leaves no personal information behind on the machine you run it on, so you can. Experimenting with metaprogramming by verifying constraints during compilation time one of the simplest and safest methods for a start i always wanted to be somebody, but now i realize i sholdvebeen more specific.
Therefore, i call this projecttechnique template metaprogramming programming. Template metaprogramming map metainformation metafunctions membre traits traits classes traits templates lists and trees as nested templates computing numbers fibonacci control structures computing types if,switch, while,do,for computing code ewhile,edo, efor expression templates 15. And inspiring introduction to template metaprogramming. This could be done to improve your programs runtime performance in exchange for slower compile times or simply to make the programmers work easier. It allows even inexperienced programmers to perform compile. Metaprogramming involves generating, combining and transforming source code. It allows even inexperienced programmers to perform compiletime computations without doing any tmp on the surface. This book is aimed at any programmer who is comfortable with idioms of the standard template library stl. Starting off the list for examples of metaprogramming is monkey patching. The reason is that tm can generate arbitrary code from the templates, but cannot modify the nontemplate code. C deref this specialization is only for leaf nodes. The use of templates can be thought of as compiletime execution. Concepts, tools, and techniques from boost and beyond by david abrahams and aleksey gurtovoy. An introduction to metaprogramming for scientific computing dr conrad sanderson senior research scientist version 1.
Template parameters can be types int including enum, short, char, bool etc. Template metaprogramming is a great technique when used correctly. The key trick is combine specialization with integral parameters. From databases and operating systems to simulations and graphics, data structures are an integral part of all programming domains. It seems really cool, make the compiler do most of the work.
Having large or multiple pdf files, both are difficult to manage. But most of the time, template metaprogramming is used and useful in small, isolated cases, basically to smooth out bumps and exceptional cases, to make a set of types look and behave uniformly, allowing you to use generic programming more efficiently. One of the most common examples of using static code i. Unsubscribe from digipen game engine architecture club. Being late to the metaprogramming party, i make no claim of having invented the techniques in this article. With variadic templates, parameter packs and template aliases. An introduction to template metaprogramming barney dellar software team lead toshiba medical visualisation systems.
The two newer standards are not used in the code so that the examples can be rich, illustrate the point, and be run with confidence. It is quite difficult to follow, specially because the practical applications shown are very abstract. Template function can be executed at runtime and constexpr functions can be templated. I was motivated to write this after i read eric nieblers thoughtprovoking tiny metaprogramming library article. Template metaprogramming tmp is a metaprogramming technique in which templates are used by a compiler to generate temporary source code, which is merged by the compiler with the rest of the source code and then compiled. How to split or merge pdf files manually sysinfotools blog. For merging, we open a file and read it character by character and store the read contents in the merged file then repeat this for the second file. The standard library offers several examples of unary type predicates in the. In the examples below we use some useful metafunctions for testing types and. Meta is a macro which exploits template metaprogramming for creating a. The first metaprogram history is just on damn thing after another nicolas cage inspiring. Generally, constexprbased solutions are simpler, and promise to get much easier with future versions of the language. I have very simple program that uses tmp,it calculates the square of a number, but it doesnt seem to.
Because of the renumbering done at each merge, the compilation time. C style arrays but, what if we want to return an array with 5 elements. Examples exhibiting the integrated metaprogramming model are presented after. Template metaprogramming can be used to automatically produce the right type. I have data structures lets call each a resource that are stored in posix shared memory. In this article, i will discuss about how to split pdf file into multiple smaller parts and merge multiple pdf files into a single file at anytime from anyplace without affecting the content and file structure. Template metaprogramming john edwards of thatgamecompany digipen game engine architecture club. What weve done now is program a little function or subroutine that is evaluated compiletime, using tmp. That doesnt work if the language doesnt support metaprogramming well. Template metaprogramming techniques for conceptbased. Nov 04, 2019 apply common algorithms such as heapsort and merge sort for string data types.
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