Supports this code:

widget: @python type
= {
    value: int;
    operator=: (out this, i: int) = { value = i; }

    add: (inout this, i: int) -> int
        = { value += i; return value; }

    shout: (this, s: std::string) -> std::string
        = s + "!";
}

Being invoked from Python like this:

import widgetlib

w = widgetlib.widget(10)
print(w.add(5))         # prints 15
print(w.add(i=7))       # prints 22
print(w.shout("hello")) # prints "hello!"

I'm not checking in a test case though because this is proof-of-concept only, currently hardwired to generate pybind11 and bash .sh invoking g++-10

…ing lowering

* Update for regex 20 lookbehind test.

Removed cpp file and added cpp2 file.

* Fix for name lookup issues with MSVC.

* Add missing files.

* Refactor of autodiff with generalized traversal.

Added test for autodiff.

* Handling of expression lists.

* Handling of expresson terms.

* Handling of function calls.

* Added special handling of math functions.

* Added declarations and statements to simple_traversal.

* Handling if/else statements.

* Added handling of direct return.

* Stub handling of value declarations.

* Added example for non differential variable.

* Added handling of while and do while loops.

* Handling of for loops and added special functions.

* Unified function call handling.

* Proper handling of initializer expressions.

* Fix initializer problem.

* Suffix can now be user defined.

* Added second order test.

* Remove initialization order workaround.

* Taylor polynomial propagation implementation.

* Basic handling of higher order derivatives and handling of add and minus.

* Added  handling for multiply and division.

* Higher order handling for special functions.

* Remaining tests for higher order derivatives.

* Declaration lookup and lookup of function return name.

* Basic changes for adding new things for the differentiation.

* Moved handling of types and functions to autodiff_declaration_handler.

* Added handling for differentiation of symbols outside of metafunction type declaration.

* Basic differentation for type and namespace value declarations.

* Refactor of autodiff_expression_handler.

The expression handler no longer generates the assignments. It stores
the primal and forward expression. The assignments can now be generated
with helper functions or by accessing the expressions.

* Handling of member access.

* Moved assignment handling code to proper traverse function.

* Added type differentiation for types without member functions.

* Handling of member function calls.

First basic setup for declared variable lookup.

* Handling of prefix + and -.

* Basic preperations for reverse mode AD.

* Refactor of diff string to structure.

Currently placeholder that defaults to the forward derivatives.

* Reverse handling of function declaration.

* Reverse differentiation of additive expressions.

* Basic handling of multiplication and division.

* Fix for to_string of expressions.

* Activity analysis for variables and functions.

* Update for tests and acitivity analysis.

* Added tests for combined binary expressions.

* Handling of special functions for reverse mode.

* Added handling of function calls for reverse.

* Handling of statement parameters for loops in forward mode.

* Reverse handling of for loops.

* Temp.

* Build clean with GCC 10 and Clang 21, and update regression test results

* Bugfix for passive variables in addition or subtraction statements.

* Add an AD unit test

---------

Co-authored-by: Herb Sutter <herb.sutter@gmail.com>

* Documentation for autodiff.

* Fix remarks and build errors.

* Trying to fix msvc.

* Update results for regression tests.

* Make AD warning be not an error so regression tests run

---------

Co-authored-by: Herb Sutter <herb.sutter@gmail.com>

And update dates to 2026

* Add runtime check for modulo by zero

* Rerun regression tests

One of the tests now hits an MSVC error I've seen before, related to using std::source_location via module std import -- it doesn't manifest on any other compiler, or in MSVC using std headers. So the error is spurious, but I'm not able to debug it or find a workaround, and I don't want to record regression test failures just because of that use case where 'module std currently doesn't work.' So this commit also changes all -pure regression tests to use headers, not modules, at least for now until modules work better

---------

Co-authored-by: Herb Sutter <herb.sutter@gmail.com>

* CI Update runners in the build-cppfront.yaml

* CI Update runners in the regression-tests.yml

* CI Use -include-std cppfront option for pure regression tests

Including regression test cases

TODO: write docs

Basic usage is

    try {
        ...
    }
    catch( i: int ) { use(i); } // catch an int
    catch( _ ) { } // catch everything

And bump build number

And 'encapsulated' and 'noncopyable' metaclasses

Signed-off-by: Herb Sutter <herb.sutter@gmail.com>