README.md

C++ Debug Library

A C++17 header-only debugging library for competitive programming. Partially vibe-coded.

See also: philip82148/cpp-dump

Usage

#include "debug.hpp"

int main() {
    int x = 42;
    std::vector<int> v = {1, 2, 3};
    std::map<std::string, int> m = {{"a", 1}, {"b", 2}};

    dbg(x);           // Single variable
    dbg(v);           // Container
    dbg(x, v, m);     // Multiple variables
}

Features

• Single argument: dbg(variable)
• Multiple arguments: dbg(var1, var2, var3)
• Output to stderr with ANSI colors
• Automatic formatting for:
  • Built-in types (int, bool, char, float, pointers)
  • STL containers (vector, set, map, etc.)
  • Smart pointers and optional types
  • Tuples and custom types
• Custom struct formatting: DBG_FORMAT_STRUCT or through operator<<

Customization

Modify the global configuration before using debug functions:

#include "debug.hpp"

// Modify default options
dbg::config::fixed_float = true;        // Use fixed precision for floats
dbg::config::float_precision = 3;       // Float precision
dbg::config::enable_colors = false;     // Disable colors
dbg::config::max_container_elements = 10; // Max elements shown in containers

// Or using an immediately invoked lambda
namespace dbg::config {
    int _ = []() {
        fixed_float = true;
        float_precision = 3;
        enable_colors = false;
        max_container_elements = 10;
        return 0;
    }();
}

Available options in dbg::config:

• fixed_float - Use fixed precision for floating point numbers
• float_precision - Precision for floating point numbers
• trivial_string - Whether strings are considered trivial
• enable_colors - Enable/disable ANSI color output
• max_container_elements - Max elements shown before truncation (set to -1 for unlimited)
• show_multiplicity - Show multiplicity in multisets/maps

Custom Struct Formatting

For custom structs without operator<<, use the formatting macros:

struct Person {
    std::string name;
    int age;
    double height;
};

DBG_FORMAT_STRUCT(Person, name, age, height);

int main() {
    Person p{"Alice", 25, 5.6};
    dbg(p);  // Output: [main:11] p = Person{name=Alice, age=25, height=5.6}
}

Custom Type Triviality

Types can control their "triviality" for container formatting by declaring:

struct MyType {
    // ... members ...
    static constexpr bool is_simple = true;  // Forces single-line container formatting
};

Without is_simple = true, non-POD types format containers with newlines and indentation.