tree 31f7cd5d9fcc490691419227d2c3a5b143d27377
parent bcbaff6656070f9d81d41dac664cc765c7962f22
author Sameer Agarwal <sameeragarwal@google.com> 1773786348 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1774200318 -0700

[modernize] Modernize ProductManifold using fold expressions

Modernize ProductManifold using C++17 fold expressions and std::index_sequence
to replace recursive implementations of Plus, Minus, and their Jacobians.
This simplifies the code, removes the need for auxiliary recursive ...Impl
methods, and improves index handling by using std::get<I> instead of
pointer arithmetic.

Change-Id: I28498216d8daae7485c382140613fd85519fa42c