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Fixed-Length String

LibXR::String<N> is a template class designed for fixed-length strings. It supports safe construction, comparison, search, appending, and more, making it suitable for resource-constrained embedded environments.

Feature Overview​

  • Fixed Length: The maximum length is specified via the template parameter MaxLength. Internally, it uses std::array<char, MaxLength+1> and is always null-terminated (\0).
  • Safe Operations: Most methods include boundary checks and assertions to prevent out-of-bounds access.
  • C-Style String Compatible: Supports construction from const char* or strings with a specified length. The Raw() method retrieves the underlying string.
  • Appending and Searching: Supports += for appending and Find() for substring search.
  • Full Comparison Operators: Supports ==, !=, <, >, <=, >=, including comparisons between different String<N> lengths.

Usage Example​

LibXR::String<32> s1("hello");
s1 += " world";
int idx = s1.Find("lo");  // returns 3
auto sub = s1.Substr<5>(6);  // extracts 5 characters starting from index 6

API Reference​

Constructors​

  • String() – Constructs an empty string.
  • String(const char* str) – Constructs from a C-style string.
  • String(const char* str, size_t len) – Constructs from a string with a specified length.

Basic Methods​

  • const char* Raw() const – Returns the underlying C-style string.
  • size_t Length() const – Returns the current string length.
  • void Clear() – Clears the string.
  • int Find(const char* str) const – Finds the position of a substring; returns -1 if not found.
  • template <unsigned int SubStrLength> String<SubStrLength> Substr(size_t pos) const – Extracts a substring starting at a given position.

Operators​

  • += – Appends a C-style string.
  • [] – Accesses characters by index (with boundary assertion).
  • Comparison operators – ==, !=, <, >, <=, >= are supported across String<N> of different lengths.