Question

Suppose I am writing a template library consisting of a function template

template<T> void f(T);

with the requirement that it works with a predefined set of classes A, B, C, and D, e.g., the following must compile:

template<> void f(A);
template<> void f(B);
template<> void f(C);
template<> void f(D);

Which test framework can I use to write test cases that captures this requirement at runtime instead of failing at compilation of the test code? In another word, I would like the framework to instantiate the templates at runtime and produce a nicely formatted error report if a subset of them fails.

I know I can forego test frameworks altogether and simply write a simple cc file containing the 4 lines above. But I was hoping I could incorporate this requirement into regular, standard test cases for generation of test status reports. For example,

test f works with A: passed.
test f works with B: passed.
test f works with C: failed!  Cannot cast type C!
test f works with D: passed.

3 of 4 tests passed.
1 of 4 tests failed.

Answer 1

Write a test case that spawns the compiler… that’s how e.g. autoconf tests for existence of features.