constexpr-string

This library provides a ConstexprString class which gives you the possibility to work with your strings in compile-time.

• Written in C++11

The class implements:

• concatenation with other strings
• replace
• substr
• find
• rfind
• findFirstOf
• findFirstNotOf
• findLastOf
• findLastNotOf
• allOf
• iterator over all string characters
• equality comparator

Non-member functions:

• cstrlen
• cstreq
• toLower
• toUpper
• cmin

Integration with CMake

add_subdirectory(external/constexpr-string)
target_link_libraries(your-target
    PRIVATE constexpr-string
)

Tests can be allowed by setting BUILD_TESTS variable to TRUE:

mkdir -p build && cd build
cmake -DBUILD_TESTS=1 ..

How to use?

Just include the header and you're ready to go:

#include <iostream>
#include <constexpr-string/constexpr-string.hpp>

struct IsHexChar {
    constexpr bool operator()(const char c) const {
        return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');
    }
};

int main() {
    constexpr auto tale = String("Let me tell you a tale");
    static_assert("Listen. " + tale + ", ok?" == String("Listen. Let me tell you a tale, ok?"), "String concatenation");
    static_assert(tale.replace('l', 'k') == String("Let me tekk you a take"), "Char replace");
    static_assert(tale.substr<7, 15>() == String("tell you"), "String substr");
    static_assert(tale.find('y') == 12, "String find");
    static_assert(tale.find('t', 4) == 7, "String find");
    static_assert(tale.find("tell") == 7, "String find");
    static_assert(tale.find("story") == StringNpos, "String find");
    static_assert(tale.rfind('l') == 20, "String rfind");
    static_assert(tale.findFirstOf("tlf") == 2, "String findFirstOf");
    static_assert(tale.findLastOf("tlf") == 20, "String findLastOf");
    static_assert(tale.findFirstNotOf("Let me") == 9, "String findFirstNotOf");
    static_assert(tale.findLastNotOf("tale ") == 14, "String findLastNotOf");
    static_assert(toLower(tale) == String("let me tell you a tale"), "toLower");
    static_assert(toUpper(tale) == String("LET ME TELL YOU A TALE"), "toUpper");
    constexpr auto hexStr = String("8dd42e58184249a1974295b4bb97de9a");
    static_assert((hexStr.size() & 1) == 0, "This string must have even length");
    static_assert(hexStr.allOf(IsHexChar()), "This string may contain hex chars only");
    std::cout << tale.cStr() << std::endl;
}