Add testcase

Examples/test-suite/common.mk

@@ -649,6 +649,7 @@ CPP17_TEST_BROKEN = \
 
 # C++20 test cases.
 CPP20_TEST_CASES += \
+	cpp20_lambda_template \
 	cpp20_spaceship_operator \
 
 # Broken C++20 test cases.

Examples/test-suite/cpp20_lambda_template.i

@@ -0,0 +1,12 @@
+%module cpp20_lambda_template
+
+// We just want to test that SWIG doesn't choke parsing this so suppress:
+// Warning 340: Lambda expressions and closures are not fully supported yet.
+%warnfilter(WARN_CPP11_LAMBDA);
+
+%include <std_vector.i>
+
+%inline %{
+#include <vector>
+auto templated_lambda = []<typename T>(std::vector<T> t){};
+%}