Vix.cpp

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to_bool ​

Overview ​

to_bool converts a textual input into a bool value in a safe and explicit way.

It returns:

  • expected<bool, ConversionError> on success
  • A ConversionError on failure

The input is trimmed before parsing, and keyword matching is ASCII case-insensitive.

Supported Inputs ​

The following values are accepted:

True values ​

  • "true"
  • "1"
  • "yes"
  • "on"

False values ​

  • "false"
  • "0"
  • "no"
  • "off"

Matching is case-insensitive for keyword forms.

Function Signature ​

cpp
[[nodiscard]] VIX_EXPECTED_CONSTEXPR expected<bool, ConversionError>
to_bool(std::string_view input) noexcept;

Error Handling ​

to_bool returns structured errors instead of throwing.

Possible Error Codes ​

Error CodeDescription
EmptyInputInput is empty after trimming
InvalidBooleanInput does not match any accepted value

Example Usage ​

cpp
#include <vix/conversion/ToBool.hpp>
#include <iostream>

using namespace vix::conversion;

void example()
{
    auto v = to_bool("YES");

    if (v)
        std::cout << "Parsed value: " << (*v ? "true" : "false") << "\n";
    else
        std::cout << "Error parsing boolean\n";
}

Implementation Notes ​

  • Input is trimmed before evaluation.
  • Comparison is ASCII case-insensitive using a lightweight internal helper.
  • No heap allocations.
  • Fully constexpr-compatible (depending on build configuration).
  • No exceptions are thrown.

Design Philosophy ​

to_bool follows Vix principles:

  • Explicit results via expected
  • No hidden conversions
  • No implicit exceptions
  • Clear, predictable behavior