p-ranav / Repr

Highlights

• Header-only library
• Requires C++17
• MIT License

Getting Started

repr is a header-only library. Add include/ to your target_include_directories and include <repr/repr.h>.

repr(value) returns a printable string representation of value. To achieve this, repr uses libfmt, magic_enum and boost::pfr, and provides a nice convenience function.

repr() supports fundamental types, strings, containers, container adapters, aggregate-initializable classes/structs and chrono types.

#include <repr/repr.h>
#include <vector>
#include <iostream>

int main() {
  std::vector<std::vector<int>> mat{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
  std::cout << repr(mat) << "\n";
  // {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}

  std::map<std::string, std::vector<int>> map{{"a", {1, 2, 3}}, {"b", {4, 5, 6}}, {"c", {7, 8, 9}}};
  std::cout << repr(map) << "\n";
  // {{"a", {1, 2, 3}}, {"b", {4, 5, 6}}, {"c", {7, 8, 9}}}

  std::optional<int> opt;
  std::cout << repr(opt) << "\n";
  // nullopt

  enum class Color { RED = 2, BLUE = 4, GREEN = 8 };
  Color color = Color::BLUE;
  std::cout << repr(color) << "\n";
  // BLUE
}

Aggregate-Initializable Structs

// standard includes
#include <chrono>
#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <optional>
using namespace std::literals::chrono_literals;

// library includes
#include <repr/repr.h>

// Some user-defined struct
struct my_struct {
  std::map<std::string, std::vector<int>> map{{"a", {1, 2}}, {"b", {3, 4}}};
  std::optional<float> baz{3.14};
  std::tuple<bool, char, std::string> tup = std::make_tuple(true, 'A', "Lisa Simpson");

  enum class log_level { info, warn, error };
  log_level level{log_level::info}; 

  struct nested_struct {
    std::chrono::nanoseconds start{5345ns};
    std::chrono::nanoseconds end{9876ns};
  };
  nested_struct ns;
};

int main() {
  my_struct s;

  std::cout << repr(s) << "\n";
  // {{{"a", {1, 2}}, {"b", {3, 4}}}, 3.14, {3, 'A', "Lisa Simpson"}, info, {5345ns, 9876ns}}
}

Building

git clone https://github.com/p-ranav/repr
cd repr
mkdir build && cd build
cmake .. && make && make install

Contributing

Contributions are welcome, have a look at the CONTRIBUTING.md document for more information.

License

The project is available under the MIT license.