A C++ Debugging Library that Can Print Vectors, Maps, Sets, Tuples, and All

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Hi Codeforces! I'm a Japanese graduate student, and I've been programming as a hobby since I was 11. I started CP last year, and since then, I've been working on a C++ debugging library that can print variables of almost any type, like vectors, maps, tuples, and more. In this blog, I want to share it with you. Link: https://github.com/philip82148/cpp-dump

Feature Summary

A Wide Variety of Supported Types Section
Example Code
Large Image

Auto Indent Section
Example Code
Large Image

Customizable Output Color Section
Example Code
Large Image

20+ Manipulators to Change the Display Style Section
Example Code
Large Image

The string representation of variables is similar to JavaScript, Python, and C++ syntax. The output is readable without being overloaded with information. (You can add more details using manipulators if you want.)
The filename, line number, and function name can be included in the output.
By using macros, cpp-dump supports user-defined types as well. There is no need to write new functions for printing.

See the Features section of the README for details.

Simple Usage

Pass variables to the cpp_dump() macro. For more detailed usage, please see README of the repo.
Full Example Code

#include <bits/stdc++.h>
#include "path/to/cpp-dump/cpp-dump.hpp"
using namespace std;

int main() {
  vector<vector<int>> my_vector{{3, 5, 8, 9, 7}, {9, 3, 2, 3, 8}};
  cpp_dump(my_vector);
}

Let's try it!

Clone the repo(git clone https://github.com/philip82148/cpp-dump) or download it (zip) (tar.gz) from Releases.
Compile & run the code below to test the library

#include <bitset>
#include <complex>
#include <iostream>
#include <map>
#include <optional>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <utility>
#include <variant>
#include <vector>

#include "path/to/cpp-dump/cpp-dump.hpp"
namespace cp = cpp_dump;
using namespace std;

int main() {
  bool my_bool = true;
  double my_double = 3.141592;
  int my_int = 65;
  char my_char = 'a', LF_char = '\n';
  string my_string = "This is a string.";
  int *int_ptr = &my_int;
  void *void_ptr = &my_int;
  vector<vector<int>> my_vector{{3, 5, 8, 9, 7}, {9, 3, 2, 3, 8}};
  set<char> my_set{'A', 'p', 'p', 'l', 'e'};
  map<int, int> my_map{{2, 6}, {4, 6}, {5, 3}};
  multiset<char> my_multiset{'A', 'p', 'p', 'l', 'e'};
  multimap<int, int> my_multimap{{2, 4}, {4, 6}, {5, 3}, {4, 7}};
  pair<int, char> my_pair{8, 'a'};
  tuple<int, double, string> my_tuple{7, 4.5, "This is a string."};
  queue<int> my_queue;
  priority_queue<int> my_priority_queue;
  stack<int> my_stack;
  for (auto v : {1, 2, 3, 4, 5}) my_queue.push(v), my_priority_queue.push(v), my_stack.push(v);
  bitset<8> my_bitset(0x3a);
  complex<double> my_complex{1.0, -1.0};
  optional<int> my_optional{15};
  variant<int, string> my_variant{"This is a string."};
  vector<pair<int, string>> vector_of_pairs{{1, "apple"}, {3, "banana"}};

  CPP_DUMP_SET_OPTION(max_line_width, 100);
  CPP_DUMP_SET_OPTION(max_iteration_count, 10);

  clog << "\n// Basic Type" << endl;
  cpp_dump(my_bool, my_double, my_int), cpp_dump(my_string, my_char, LF_char);
  cpp_dump(int_ptr, void_ptr, nullptr);

  clog << "\n// Container" << endl;
  cpp_dump(my_vector);

  clog << "\n// Set/Map" << endl;
  cpp_dump(my_set), cpp_dump(my_map);

  clog << "\n// Multiset/Multimap" << endl;
  cpp_dump(my_multiset), cpp_dump(my_multimap);

  clog << "\n// Tuple" << endl;
  cpp_dump(my_tuple), cpp_dump(my_pair);

  clog << "\n// FIFO/LIFO" << endl;
  cpp_dump(my_queue), cpp_dump(my_priority_queue), cpp_dump(my_stack);

  clog << "\n// Other" << endl;
  cpp_dump(my_bitset), cpp_dump(my_complex);
  cpp_dump(my_optional, nullopt), cpp_dump(my_variant);

  clog << "\n// Combination" << endl;
  cpp_dump(vector_of_pairs);

  vector<vector<int>> some_huge_vector(100, vector<int>(100));
  vector<vector<unsigned int>> unsigned_int_vector(100, vector<unsigned int>(100));

  for (int i = 0; i < 100; ++i) {
    for (int j = 0; j < 100; ++j) {
      some_huge_vector[i][j] = ((i + 1) * 7 % 19 - 9) * ((j + 1) * 3 % 19 - 9);
      unsigned_int_vector[i][j] = abs(some_huge_vector[i][j]);
    }
  }

  clog << "\n// Manipulator Test" << endl;
  cpp_dump(some_huge_vector | cp::back() | cp::both_ends() | cp::dec(2));
  cpp_dump(some_huge_vector | cp::dec(2) | cp::index());
}

There are other installation methods, too. Please see the Installation section of the README for details.

Recommended usage in competitive programming

cpp_dump(vars...) is long, so let's shorten it to dump(vars...) by macro. For details, see For Competitive Programming Use section of the README.

#ifndef ONLINE_JUDGE
#include "path/to/cpp-dump/cpp-dump.hpp"
#define dump(...) cpp_dump(__VA_ARGS__)
#else
#define dump(...)
#endif

News

v0.7.0 released on August 19 has lots of new features.
If you're using an older version, please update it! (For git users, run git pull)

Conclusion

I hope this library helps!
Also, if you could upvote this blog and give a star to the repo, I would really appreciate it.

#include <array> #include <deque> #include <iostream> #include <list> #include <map> #include <queue> #include <set> #include <stack> #include <unordered_map> #include <unordered_set> #include <utility> #include <vector> using namespace std; // Helper to identify if a type is a pair template <typename T> struct is_pair : false_type {}; template <typename T, typename U> struct is_pair<pair<T, U>> : true_type {}; // Helper type traits to determine if a type is printable directly template <typename T> struct is_directly_printable : integral_constant<bool, is_arithmetic<T>::value || is_same<T, string>::value> {}; // Declare dbg to enable recursive calls template <typename Container> void dbg(const Container &container); // Special handling for array types template <typename T, size_t N> void dbg(const T (&array)[N]) { for (size_t i = 0; i < N; ++i) { print_element(array[i], is_directly_printable<T>{}); cerr << " "; } cerr << endl; } // Specialization for std::stack template <typename T, typename Container> void dbg(const std::stack<T, Container> &stk) { auto copy = stk; // Make a copy of the stack to consume it cerr << "["; while (!copy.empty()) { print_element(copy.top(), is_directly_printable<T>{}); copy.pop(); if (!copy.empty()) cerr << ", "; } cerr << "]" << endl; } // Specialization for std::queue template <typename T, typename Container> void dbg(const std::queue<T, Container> &q) { auto copy = q; // Make a copy of the queue to consume it cerr << "["; while (!copy.empty()) { print_element(copy.front(), is_directly_printable<T>{}); copy.pop(); if (!copy.empty()) cerr << ", "; } cerr << "]" << endl; } // Print a single element based on its type template <typename T> void print_element(const T &element, true_type) { cerr << element; } template <typename T> void print_element(const T &element, false_type) { if constexpr (is_pair<T>::value) { cerr << "("; print_element(element.first, is_directly_printable< typename decay<decltype(element.first)>::type>{}); cerr << ", "; print_element(element.second, is_directly_printable< typename decay<decltype(element.second)>::type>{}); cerr << ")"; } else { dbg(element); } } // General dbg function for containers template <typename Container> void dbg(const Container &container) { for (const auto &element : container) { print_element(element, is_directly_printable<typename Container::value_type>{}); cerr << " "; } cerr << endl; } // ####################################################################################### template <typename... Args> void dbgs(Args... args) { ((std::cerr << args << ", "), ...); std::cerr << std::endl; }

Комментарии (37)

Написать комментарий?

tawhidmonowar

7 недель назад, # |

This looks interesting! I'll definitely try it out!

I used to debug code with the following snippet, which I learned in a competitive programming course. It allows you to print any type of variable and pass multiple arguments to the debug() function. It's been really helpful for debugging.

Snippet

#define debug(...) _f (#__VA_ARGS__, __VA_ARGS__)

template <typename Arg1>
void _f (const char* name, Arg1&& arg1)
{
    cout << name << " : " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void _f (const char* names, Arg1&& arg1, Args&&... args)
{
    const char* comma = strchr (names + 1, ',');
    cout.write (names, comma - names) << " : " << arg1 << " | ";
    _f (comma + 1, args...);
}

void solve()
{
    string str = "Hello World!";
    int x=5, y=1, z=4;
    bool isTrue = false;

    debug(str, x, y, z, isTrue);
}

/*  

Output:
str : Hello World! |  x : 5 |  y : 1 |  z : 4 |  isTrue : 0

*/

→ Ответить

khaled_eg

7 недель назад, # ^ |

what about arrays and vectors?

tyristik

But can it print my profile picture?

Pirate_King

+27

Just need to add this function

void print_tyristik_pfp(){
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%@@%%%#%###*%###**#*######%%%%%%%%%%%%%%%%%%%%%%%%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%@@%%*##*####%####**##%%%###%%%%%%%%%%%%%%%%%%%%%%%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%%%%@@%%%+##*#%%%%%%%#####%#####%%%%%%%%%%%%%%%%%%%%%%%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%%%@@@%%#*###%%%%%%%%%%%##***#%%%%%%%%%%%%%%%%%%%%%%%%%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%%@@@%#%##%%%%%%%%%%%####****#%%%%%%%%%%%%%%%%%%%%%%%%%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%@%%%%%%#%%%%%%%%#####**++**##%%%%%%%%%%%%%%%%%%###%%%%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%#####***+++***##%%%%%%##############%%%%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%%%#%%%%%@%%######****++++***###%%@@@%######%%##%######%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%%#######%%%####*****+++++****###%%%%%%######%%%%%#######"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%%%###*****####****++++++++***####%%%#%%###################"<<endl;
cout<<"%#%%%%#%%%%%%%%%%%%%%########*******++++++*******#####%%#%@#**################%"<<endl;
cout<<"%##%%##%%%%%%%%%%%%%%%###%%%%#*************#******###%%%%%%###################%"<<endl;
cout<<"%######%%%%%%%%%%%%%%%#######*#*****####%######****##%%%%%##*%################%"<<endl;
cout<<"%%%%%%%%%%%%%%%%%%%%%###########****#####****###****##%%%##*################%%%"<<endl;
cout<<"%#%%%%%%%%%%%%%%%%%#####%%%%####*****#########*#****##%%%#***+*#############%%%"<<endl;
cout<<"######%%%%%%%%%%#%######%###***********##%%%%%##****##%%#*#%#++*########%##%%%@"<<endl;
cout<<"%###%%%%%%%%%%%%%%#####**##**************#**********#####%%%#*+=+*####%%%%%%%@@"<<endl;
cout<<"%%##%%%%%%%%%%######***#*****##*********************#####%#%%#*+==+*%%%%%%%%%@@"<<endl;
cout<<"%#####%%%%%%%######*+++*#***##%##*##%##****+++******#####%%%%#*++==+#%%%%%%%%@@"<<endl;
cout<<"########%%%######*++=++*#**##%%%####%%#####*********####%%%###*+++==+#%%%%%%%@@"<<endl;
cout<<"#######%%######*+===+***##*#%%%%%%##%%#%%%###******#####%%#%***++====+#%%%%%%%@"<<endl;
cout<<"#######%%#####*+====++**##*#%%%%%%#%%%%%%%%%##*****#####%%*%*#*=++=====#%%%%%%@"<<endl;
cout<<"%#####%%####*+==+===++***#*#%%%%%##%%%%%##%%%%#***######%%#%##*+++======#%%%%%@"<<endl;
cout<<"%#####%###*++===+=+=++*#*##*%%%##%###%%#%%%%%##***######%%%%##+*+========#%%%%@"<<endl;
cout<<"%########++++++=+=+++**#*##*##%%#%%%%%%%%%%%##****#####%%%%%##+*++=+=====+#%%%@"<<endl;
cout<<"%#######++++++++++=++****##*##%@%%%%%%%%%#%%*#****#####%%%%##***+++++=====+#%%@"<<endl;
cout<<"%######+++++++++++++******##*##@@%%%%%%#####*#***#####%%#%%##++++=++=======+#%@"<<endl;
cout<<"%#####*+++++++=+++++*****#%#**#%%#######*##******#####%##%%#*+*+++++++===-==+#%"<<endl;
cout<<"%####*+++++=+++++++***+*#%@#**###%#**##*##*******####%###%##+***==+++====-====#"<<endl;
cout<<"%####+*++++=+++*********#%%%#**###***##*#*******####%#######+**++++*+=========+"<<endl;
cout<<"%###++*++++++++++*****+*%#*%#**####*##*+********###########*****++**+=+=======+"<<endl;
cout<<"%##++**+++++**********+*#%#%##*##**************###########*****+++*++++=======+"<<endl;
cout<<"%#*****++***************#%%%%#####**********#*###########******++**++++++=====+"<<endl;
cout<<"%#**********************###%%##************#*###########******++***+++++++++==+"<<endl;
cout<<"#************************#*#%%##**********##*##########*******+****++++++++++=+"<<endl;
cout<<"#************************#*#%%##*********##**#########*************+++++++++++*"<<endl;
cout<<"**************************#*#%%##*******##**#########*************+++***+**+++*"<<endl;
cout<<"#*************************###%%%%#########*##########*************+++*+***+****"<<endl;
cout<<"##*************************#**#%%%%#################**************+************"<<endl;
cout<<"#***************************#**#%%@%###############******************+*+*******"<<endl;
cout<<"#*******************************##%@%######%%#####***************+************#"<<endl;
cout<<"#********************************#%%@@@%%%%%#####****************+************#"<<endl;
cout<<"##*#******************************##%%%@%%%%####***************+**************#"<<endl;
}

Bro is the GOAT, wow

Yelo885599

Bro you have to reveal how you did this godly thing

There are many websites that do that lol. Not a big deal

immix

← Rev. 2 →

Is it possible to support custom class/structure? (just like print/disp in gdb do)

Edit: I see this can be achieved by using some macros or operator, but it would be more convenient if a default result can be provided (maybe diffcult to implement in c++)

philip82148

Yes..., it is difficult to provide default results for custom classes in C++.
Using the CPP_DUMP_DEFINE_EXPORT_OBJECT_GENERIC macro is the easiest way to support user types.

C++ reflection black MAGIC XD

← Rev. 5 →

If you want to customize the string representation of a custom class more flexibly, you can do it as follows.

Code

#include "path/to/cpp-dump/cpp-dump.hpp"

namespace cpp_dump::_detail {

template <>
inline std::string export_var(
    const YOUR_TYPE &value,
    const std::string &indent,
    std::size_t last_line_length,
    std::size_t current_depth,
    bool fail_on_newline,
    const export_command &command
) {
  return "Implement code to return the string representation of YOUR_TYPE here";
}

}  // namespace cpp_dump::_detail

#define dump(...) cpp_dump(__VA_ARGS__)

int main() {
  YOUR_TYPE var;
  dump(var);
}

For reference, you can support AtCoder Library's modint by calling the function recursively like this.

989

How do I turn off the color output?

Pls see the end of the Customizable output color section.

CPP_DUMP_SET_OPTION(es_style, cp::types::es_style_t::no_es);

← Rev. 7 →

Why does it display the message as an error in cp editor?

cpp_dump() outputs to the standard error output (std::clog) by default. So, for example, if you want to change the output destination to the standard output (std::cout), you can do it as follows.

#include "path/to/cpp-dump/cpp-dump.hpp"
// other settings...

template <>
inline void cpp_dump::write_log(std::string_view output) {
  std::cout << output << std::endl;
}

int main() ...

thank you very much

Ur welcome

Here is a list of all the supported types: Supported types
Since cpp_dump() prints variables recursively, it can print any combination of nested containers from the list.

AnikateKoul

Hi. I found your library really helpful.

Just wanted your help on this thing :

The dump function is working perfectly fine when the output is shown on terminal. But when I am using the CPH Judge VS Code extension, the output being displayed is something like this :

[0m[02m[codeforces.cpp:85] [0m[36mv[0m[02m => [0m[02m[ [0m1[0m[02m, [0m2[0m[02m, [0m3[0m[02m, [0m4[0m[02m, [0m5[0m[02m ][0m

I know you might not be aware of the CPH extension, but any suggestion from your side would be of great help.

Thanks.

I use cp editor but have encountered the same problem.

1) Disable the display of colored text using this code:

This code

CPP_DUMP_SET_OPTION(es_style, cpp_dump::types::es_style_t::no_es);

2) cpp_dump() outputs to the standard error output (std::clog) by default. So, for example, if you want to change the output destination to the standard output (std::cout), you can do it as follows.

this is the full code I'm using

code

#include <bits/stdc++.h>

#ifndef ONLINE_JUDGE
#include "/home/muhammadjon/Documents/debug/cpp-dump-0.7.0/cpp-dump.hpp"
#define dump(...) cpp_dump(__VA_ARGS__)
template <>
inline void cpp_dump::write_log(std::string_view output) {
    std::cout << output << '\n';
}
#else
#define dump(...)
#define CPP_DUMP_SET_OPTION(...)
#define CPP_DUMP_DEFINE_EXPORT_OBJECT(...)
#define CPP_DUMP_DEFINE_EXPORT_OBJECT_GENERIC(...)
#define CPP_DUMP_DEFINE_EXPORT_ENUM(...)
#define CPP_DUMP_DEFINE_EXPORT_ENUM_GENERIC(...)
#endif

using ll = long long;
using ld = long double;
using ull = unsigned long long;
#define str string

#define all(v)  v.begin(), v.end()
#define fi      first
#define se      second
#define pb      push_back
#define ent     cout << "\n";
#define sz(v)   ll(v.size())

using namespace std;

const long long MOD = 1e9+7, inf = 1e18;

void run(ll tnm) {
    
}

int32_t main() {
    CPP_DUMP_SET_OPTION(es_style, cpp_dump::types::es_style_t::no_es);
    #ifdef ONLINE_JUDGE
        // freopen("input.txt","r",stdin);
        // freopen("output.txt","w",stdout);
    #endif
    ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);

    ll ttest=1;
    cin >> ttest;

    for (ll test_number=1; test_number<=ttest; test_number++) {
        run(test_number);
    }

    return 0;
}

Yeah, the output is now being formatted perfectly.

Thanks a lot!

For reference, the garbled character is '\x1b' (a char with a hex value of 0x1b), which is called an escape sequence and controls color.
Running this in the terminal helps you understand this.

Command

echo "\x1b[0m\x1b[02m[codeforces.cpp:85] \x1b[0m\x1b[36mv\x1b[0m\x1b[02m => \x1b[0m\x1b[02m[ \x1b[0m1\x1b[0m\x1b[02m, \x1b[0m2\x1b[0m\x1b[02m, \x1b[0m3\x1b[0m\x1b[02m, \x1b[0m4\x1b[0m\x1b[02m, \x1b[0m5\x1b[0m\x1b[02m ]\x1b[0m"

Somehow I couldn't use cpeditor in my environment, so I didn't test, but probablly cpeditor doesn't recognize escape sequences.

This is advanced knowledge, but a terminal is treated as a file in macOS or Linux.
You can get the path of a terminal by the tty command.

tty
# In my terminal, I got "/dev/pts/7"

(Command to help you understand this)

Note: echo "something" > filepath writes to a file.

# Run this in another terminal, and you'll see the output in the first terminal.
echo "\x1b[0m\x1b[02m[codeforces.cpp:85] \x1b[0m\x1b[36mv\x1b[0m\x1b[02m => \x1b[0m\x1b[02m[ \x1b[0m1\x1b[0m\x1b[02m, \x1b[0m2\x1b[0m\x1b[02m, \x1b[0m3\x1b[0m\x1b[02m, \x1b[0m4\x1b[0m\x1b[02m, \x1b[0m5\x1b[0m\x1b[02m ]\x1b[0m" > /dev/pts/7

So, you can write the output of cpp_dump() to the terminal while using cpeditor like this.

#include <bits/stdc++.h>
#include "path/to/cpp-dump/cpp-dump.hpp"
// other settings...

template <>
inline void cpp_dump::write_log(std::string_view output) {
  std::ofstream outfile;
  outfile.open("/dev/pts/7");
  outfile << output << std::endl;
  outfile.close();
}

int main() ...

By doing this, you can still get colored output while using cpeditor.

I did it now, and cpp_dump() doesn't output anything.

Did you change /dev/pts/7 to your own terminal's path?
The file path is the result of the tty command.

Yeah, I did it.

Does this command work? It should produce the output 'ABC' in the terminal.

# Run this in another terminal, and you'll see the output in the terminal where you run the tty command.
echo "\n\nABC\n\n" > RESULT_OF_TTY

Sorry, I just realized what you want to do. My knowledge of linux is not that strong. So I thought this command would output the data in the cp editor itself.

It's OK. :)

arghyag

I use vim and this is best debugger i have ever seen for cp even better than mine

my debugger

my debugger cant give colored output and the structured way.

dsogari

This is really useful! Especially since it's a header-only library. I added it as a git submodule to my project.

Stanley_Shao

Great work! Upvoted and starred.

If you want to configure the library outside of the main function, you can use the CPP_DUMP_SET_OPTION_GLOBAL() macro.

#include "path/to/cpp-dump/cpp-dump.hpp"
CPP_DUMP_SET_OPTION_GLOBAL(option, value);
int main() {
  // CPP_DUMP_SET_OPTION(option, value);
  // ...
}

And here is the list of all available options: Configuration options

4 недели назад, # |

I switched to Windows and now it doesn't work, maybe I need to download another code just I don't understand it

4 недели назад, # ^ |

It's tested on Windows too. It requires C++17 or higher. Are you using the correct version? If you are, could you provide the error message?

command: g++ -std=c++17 main.cpp

error

Could you tell me the result of this command?

g++ --version