If we focus just on the programming cases where C++ has been heavily used, you can narrow that list down to D, Rust, Nim, and Zig. Dynamic languages or those with a heavy runtime like Python, Java, C#, and JavaScript are substantially different use cases.
Among those remaining, Swift has substantially more corporate backing, what with Apple relying on it for their massively successful iOS platform and Google trying to use it for TensorFlow.
C wrapper for C++ APIs has long been standard practice, but adds a substantial maintenance burden to C++ library authors and does not address semantics in the host language, which is a major part of this proposal. The whole proposal is based around the idea of seamless Swift to C++ interoperability. C++ has a lot of higher-level concepts that potentially can translate to similar higher-level concepts in other languages; round-tripping through a C API loses all of that.
To be clear, I like your idea - it's a grand one, and potentially solves the N+M problem once and for all. The real stumbling block for it is the C++ ABI and sheer mass of existing C++ code.
Among those remaining, Swift has substantially more corporate backing, what with Apple relying on it for their massively successful iOS platform and Google trying to use it for TensorFlow.
C wrapper for C++ APIs has long been standard practice, but adds a substantial maintenance burden to C++ library authors and does not address semantics in the host language, which is a major part of this proposal. The whole proposal is based around the idea of seamless Swift to C++ interoperability. C++ has a lot of higher-level concepts that potentially can translate to similar higher-level concepts in other languages; round-tripping through a C API loses all of that.
To be clear, I like your idea - it's a grand one, and potentially solves the N+M problem once and for all. The real stumbling block for it is the C++ ABI and sheer mass of existing C++ code.