SWIG supports the spaceship operator <=> in constant -expressions. To simplifying handling the return value is currently +expressions. To simplify handling of the return value type, it is currently treated as an integer rather than std::strong_ordering, etc. In practice we think that should do the right thing in most cases.
SWIG also recognises operator<=> which can be wrapped -if renamed. There's not currently any default renaming for the operator -or attempts to automatically map it to a three-way comparison operator -in any target languages that have one. +if renamed. There is not currently any default renaming for the operator +or any attempt to automatically map it to a three-way comparison operator +in any of the target languages.
-SWIG should parse lambda templates, but -like - non-templated lambdas they aren't currently wrapped. +SWIG should parse lambda templates, but like + +non-templated lambdas they aren't currently wrapped.