helpers.h File Reference

String, number, hash and formatting utility functions. More...

#include <cstdint>
#include <filesystem>
#include <string>
#include <string_view>
#include <utility>
#include <vector>
#include "./macros.h"

Include dependency graph for helpers.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Namespaces
namespace	vlink
namespace	vlink::Helpers
	Stateless string, number, hash and formatting helper functions.

Functions
VLINK_EXPORT int	vlink::Helpers::to_int (const std::string &str, int dv=0) noexcept
	Converts a decimal string to int.
VLINK_EXPORT int64_t	vlink::Helpers::to_long (const std::string &str, int64_t dv=0, int offset=0) noexcept
	Converts a decimal string to int64_t with an optional byte offset.
VLINK_EXPORT std::string	vlink::Helpers::double_to_string (double value, int precision=2) noexcept
	Converts a double to a string with a specified number of decimal places.
VLINK_EXPORT uint64_t	vlink::Helpers::hash_combine (uint64_t a, uint64_t b) noexcept
	Combines two 64-bit hash values into one using a mixing function.
VLINK_EXPORT void	vlink::Helpers::replace_string (std::string &str, const std::string &from, const std::string &to) noexcept
	Replaces all occurrences of from in str with to in-place.
VLINK_EXPORT std::string	vlink::Helpers::trim_string (const std::string &str) noexcept
	Strips leading and trailing whitespace from a string.
VLINK_EXPORT std::wstring	vlink::Helpers::string_to_wstring (const std::string &input) noexcept
	Converts a UTF-8 std::string to a std::wstring.
VLINK_EXPORT std::string	vlink::Helpers::wstring_to_string (const std::wstring &input) noexcept
	Converts a std::wstring to a UTF-8 std::string.
VLINK_EXPORT std::string	vlink::Helpers::string_local_to_utf8 (const std::string &local_str) noexcept
	Converts a locally-encoded string to UTF-8.
VLINK_EXPORT std::string	vlink::Helpers::string_utf8_to_local (const std::string &utf8_str) noexcept
	Converts a UTF-8 string to the locally-encoded system string.
VLINK_EXPORT std::string	vlink::Helpers::path_to_string (const std::filesystem::path &path) noexcept
	Converts a std::filesystem::path to a UTF-8 std::string portably.
VLINK_EXPORT std::vector< std::string >	vlink::Helpers::get_split_string (const std::string &str, char f) noexcept
	Splits a string by a delimiter character and returns the parts as a vector.
VLINK_EXPORT std::vector< std::string_view >	vlink::Helpers::get_split_string_view (std::string_view str, char f) noexcept
	Splits a string_view by a delimiter character returning non-owning views.
VLINK_EXPORT std::pair< std::string, std::string >	vlink::Helpers::get_pair_string (const std::string &str, char f) noexcept
	Splits a string at the first occurrence of a delimiter and returns a pair.
VLINK_EXPORT std::pair< std::string_view, std::string_view >	vlink::Helpers::get_pair_string_view (std::string_view str, char f) noexcept
	Splits a string_view at the first occurrence of a delimiter returning non-owning views.
VLINK_EXPORT uint32_t	vlink::Helpers::get_hash_code (const std::string &str) noexcept
	Computes a 32-bit FNV-1a-style hash code for a string.
VLINK_EXPORT std::string	vlink::Helpers::format_milliseconds (int64_t milliseconds, bool show_millis) noexcept
	Formats a duration in milliseconds as a human-readable time string.
VLINK_EXPORT std::string	vlink::Helpers::format_date (int64_t nanoseconds_since_epoch) noexcept
	Formats a nanosecond-precision epoch timestamp as a date-time string.
VLINK_EXPORT std::string	vlink::Helpers::format_time_diff (int32_t milliseconds) noexcept
	Formats a time difference in milliseconds as a human-readable string.
VLINK_EXPORT std::string	vlink::Helpers::format_hex_number (int64_t hex_number) noexcept
	Formats a signed 64-bit integer as a "0x..." hexadecimal string.
VLINK_EXPORT std::string	vlink::Helpers::format_hex_number (uint64_t hex_number) noexcept
	Formats an unsigned 64-bit integer as a "0x..." hexadecimal string.
VLINK_EXPORT std::string	vlink::Helpers::format_file_size (size_t size) noexcept
	Formats a byte count as a human-readable size string.
VLINK_EXPORT std::string	vlink::Helpers::format_rate_size (size_t size) noexcept
	Formats a byte-per-second rate as a human-readable string.
VLINK_EXPORT int64_t	vlink::Helpers::convert_date_to_timestamp (const std::string &date) noexcept
	Converts a date string to a Unix millisecond timestamp.
template<uint8_t SizeT>
bool	vlink::Helpers::has_startwith (const std::string &str, const char(&target)[SizeT]) noexcept
	Compile-time check whether str starts with the literal target.
template<uint8_t SizeT>
bool	vlink::Helpers::has_endwith (const std::string &str, const char(&target)[SizeT]) noexcept
	Compile-time check whether str ends with the literal target.
constexpr bool	vlink::Helpers::has_startwith (std::string_view str, std::string_view target) noexcept
	Checks whether a string_view starts with a given prefix (constexpr-friendly).
constexpr bool	vlink::Helpers::has_endwith (std::string_view str, std::string_view target) noexcept
	Checks whether a string_view ends with a given suffix (constexpr-friendly).
constexpr bool	vlink::Helpers::contains_substring (std::string_view sv, std::string_view needle) noexcept
	Checks whether a string_view contains a given substring.

Detailed Description

String, number, hash and formatting utility functions.

The Helpers namespace groups portable, stateless helper functions used throughout VLink for common tasks such as string splitting, type conversion, human-readable size formatting, and compile-time string matching.

Note

• All functions are noexcept; errors are indicated by default-constructed return values.
• Encoding conversion functions (string_local_to_utf8, string_utf8_to_local) use iconv on POSIX and the Windows ANSI code page on Windows.

Example

auto parts = vlink::Helpers::get_split_string("a,b,c", ',');
// parts == {"a", "b", "c"}
 
std::string s = vlink::Helpers::format_file_size(1536);
// s == "1.50KB"