• Use the migration guide when updating.
• Infrastructure
  • Updated required C++ standard to C++17.
  • Updated required CMake version to 3.8.
  • The macro TAO_PEGTL_NAMESPACE now contains the fully qualified namespace, e.g. tao::pegtl.
  • Added [[nodiscard]] or [[noreturn]] to most non-void functions.
• Meta-Data Layer
  • Replaced analysis_t with more general and complete rule_t and subs_t.
  • Added functions to visit all rules of a grammar.
  • Added functions to measure rule coverage of a parsing run.
  • Moved the analysis function and header to contrib.
• Error Handling
  • Replaced tao::pegtl::input_error with std::system_error and std::filesystem::filesystem_error.
  • Added must_if<>
    • Allows to define custom error messages for global errors.
    • Adds a non-intrusive way to define global parse errors for a grammar retroactively.
• Demangling
  • Removed the need for RTTI.
    • Some broken/unknown compilers will use RTTI as a fallback, without demangling.
  • Moved tao::pegtl::internal::demangle<T>() to tao::demangle<T>().
  • Improved generated code to be shorter and more efficient.
• Parse Tree
  • Removed the need for RTTI.
• Other
  • Changed std::string to std::filesystem::path for filename parameters.
  • Renamed byte_in_line to column and use 1-based counting.
  • Moved rule eolf from inline namespace tao::pegtl::ascii to tao::pegtl.
  • Changed rules in tao/pegtl/contrib/integer.hpp to not accept redundant leading zeros.
  • Added rules to tao/pegtl/contrib/integer.hpp that test unsigned values against a maximum.
  • Demoted UTF-16 and UTF-32 support to contrib.
  • Demoted UINT-8, UINT-16, UINT-32 and UINT-64 support to contrib.
  • Folded contrib/counter.hpp into json_count.cpp, count is superceded by coverage.
  • Removed right padding from contrib/json.hpp's value.
• Cleanup
  • Removed option of state's S::success() to have an extended signature to get access to the current apply_mode, rewind_mode, action- and control class (template).
  • Removed compatibility macros starting with TAOCPP_PEGTL_.
  • Removed compatibility uppercase enumerators.
  • Removed compatibility peek_byte() member functions.
  • Removed compatibility header changes.hpp from contrib.