102 lines
3.2 KiB
Markdown
102 lines
3.2 KiB
Markdown
# Boost.PFR
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This is a C++14 library for very basic reflection that gives you access to structure elements by index and provides other `std::tuple` like methods for user defined types without any macro or boilerplate code.
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[Latest documentation](http://apolukhin.github.com/magic_get/index.html)
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### Test results
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Branches | Build | Tests coverage | More info
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----------------|-------------- | -------------- |-----------
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Develop: | [](https://travis-ci.org/apolukhin/magic_get) [](https://ci.appveyor.com/project/apolukhin/magic-get/branch/develop) | [](https://coveralls.io/github/apolukhin/magic_get?branch=develop) | [details...](http://www.boost.org/development/tests/develop/developer/pfr.html)
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Master: | [](https://travis-ci.org/apolukhin/magic_get) [](https://ci.appveyor.com/project/apolukhin/magic-get/branch/master) | [](https://coveralls.io/github/apolukhin/magic_get?branch=master) | [details...](http://www.boost.org/development/tests/master/developer/pfr.html)
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### Motivating Example #0
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```c++
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#include <iostream>
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#include <fstream>
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#include <string>
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#include "boost/pfr.hpp"
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struct some_person {
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std::string name;
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unsigned birth_year;
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};
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int main(int argc, const char* argv[]) {
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some_person val{"Edgar Allan Poe", 1809};
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std::cout << boost::pfr::get<0>(val) // No macro!
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<< " was born in " << boost::pfr::get<1>(val); // Works with any aggregate initializables!
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if (argc > 1) {
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std::ofstream ofs(argv[1]);
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ofs << boost::pfr::io(val); // File now contains: {"Edgar Allan Poe", 1809}
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}
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}
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```
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Outputs:
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```
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Edgar Allan Poe was born in 1809
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```
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### Motivating Example #1
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```c++
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#include <iostream>
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#include "boost/pfr/precise.hpp"
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struct my_struct { // no ostream operator defined!
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int i;
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char c;
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double d;
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};
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int main() {
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my_struct s{100, 'H', 3.141593};
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std::cout << "my_struct has " << boost::pfr::tuple_size<my_struct>::value
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<< " fields: " << boost::pfr::io(s) << "\n";
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}
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```
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Outputs:
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```
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my_struct has 3 fields: {100, H, 3.14159}
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```
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### Motivating Example #2
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```c++
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#include <iostream>
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#include "boost/pfr/precise.hpp"
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struct my_struct { // no ostream operator defined!
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std::string s;
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int i;
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};
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int main() {
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my_struct s{{"Das ist fantastisch!"}, 100};
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std::cout << "my_struct has " << boost::pfr::tuple_size<my_struct>::value
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<< " fields: " << boost::pfr::io(s) << "\n";
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}
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```
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Outputs:
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```
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my_struct has 2 fields: {"Das ist fantastisch!", 100}
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```
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### Requirements and Limitations
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[See docs](http://apolukhin.github.com/magic_get/index.html).
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### License
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Distributed under the [Boost Software License, Version 1.0](http://boost.org/LICENSE_1_0.txt).
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