dedent.hpp

Compile‑time string dedentation.

Usage

Example

#include <iostream>
#include "dedent.hpp"

int main() {
    constexpr auto code = d::dedent(R"(
        int main() {
            return 0;
        }
    )");
    std::cout << d::sv(code);
}

Output

int main() {
    return 0;
}

Custom Tab Width

// Treat '\t' as 2 spaces instead of the default 4
constexpr auto text = d::dedent<2>(R"(
	First line
		Indented line
)");

Handling Blank Lines

• Blank lines at the very beginning and end of the input (containing only spaces, tabs, \r, \f, or \v) are removed entirely.
• Internal blank lines are preserved; each contributes a single \n to the output.

constexpr auto poem = d::dedent(R"(

    Roses are red,
    Violets are blue,

    Sugar is sweet,
    And so are you.

)");
// Resulting string_view content:
// "Roses are red,\nViolets are blue,\n\nSugar is sweet,\nAnd so are you.\n"

API Reference

d::dedent<size_t TabWidth = 4>(const char (&in)[N])

Purpose

Compile‑time dedentation of the raw string literal in, also trimming surrounding blank lines.

Template Parameter

TabWidth: Visual column count for a \t character. Defaults to 4.

Return Value

std::array<char, M> where M is the length of the dedented string plus one (for the null terminator). Suitable for constructing a std::string_view or a C‑style string.

d::sv(const std::array<char, N>& a)

Purpose

Converts the array returned by dedent into a std::string_view for convenient output or further processing.

Return Value std::string_view covering the dedented string (excluding the null terminator).

Implementation Details

The library uses internal helper functions inside the d::dt namespace, all of which are constexpr:

• sp(char): Checks for whitespace characters (, \t, \r, \f, \v).
• cw(char, TabWidth): Returns the visual leading width of a character.
• lw(string_view, TabWidth): Computes the total visual width of leading whitespace in a line.
• bl(string_view): Determines if a line is entirely blank.
• cs(string_view, maxWidth, TabWidth): Returns the number of leading characters to skip without exceeding maxWidth.

Requirements

• C++17 or later (uses std::string_view, enhanced constexpr, etc.).
• Supported on GCC 7+, Clang 5+, and MSVC 2017 15.7+.

License

This project is licensed under the MIT License. See the LICENSE file for details.