define constexpr_params parameterization helper

README.md

@@ -316,7 +316,7 @@ auto main() -> int
 <details><summary></summary>
 
 
-Tests can be parameterized by type
+Tests can be parameterized with a tuple-like
 
 ```cpp:example/type_parameterized.cpp
 #include "skytest/skytest.hpp"
@@ -344,7 +344,7 @@ auto main() -> int
 
 ```
 
-or by value
+or with a range
 
 ```cpp:example/value_parameterized.cpp
 #include "skytest/skytest.hpp"
@@ -363,9 +363,26 @@ auto main() -> int
 
 ```
 
-If parameters are defined as a static constant, `param_ref` may enable
-compile-time tests.
+If parameters are defined as a static constant, `constexr_params` and
+`param_ref` can be used to define compile-time tests.
 
+```cpp:example/constexpr_params_parameterized.cpp
+#include "skytest/skytest.hpp"
+
+auto main() -> int
+{
+  using namespace ::skytest::literals;
+  using ::skytest::constexpr_params;
+  using ::skytest::eq;
+  using ::skytest::expect;
+
+  "types with param_ref"_ctest * constexpr_params<1, 2U> =  //
+      [](auto param) {
+        return expect(eq(std::is_same_v<int, decltype(param)> ? 1 : 2, param));
+      };
+}
+
+```
 ```cpp:example/param_ref_parameterized.cpp
 #include "skytest/skytest.hpp"
 

example/BUILD.bazel

@@ -123,6 +123,12 @@ cc_test(
     deps = [":skytest_wrapper"],
 )
 
+cc_test(
+    name = "constexpr_params_parameterized",
+    srcs = ["constexpr_params_parameterized.cpp"],
+    deps = [":skytest_wrapper"],
+)
+
 cc_test(
     name = "param_parameterized",
     srcs = ["param_parameterized.cpp"],

example/constexpr_params_parameterized.cpp

@@ -0,0 +1,14 @@
+#include "skytest/skytest.hpp"
+
+auto main() -> int
+{
+  using namespace ::skytest::literals;
+  using ::skytest::constexpr_params;
+  using ::skytest::eq;
+  using ::skytest::expect;
+
+  "types with param_ref"_ctest * constexpr_params<1, 2U> =  //
+      [](auto param) {
+        return expect(eq(std::is_same_v<int, decltype(param)> ? 1 : 2, param));
+      };
+}

scripts/README.md.tmpl

@@ -109,19 +109,21 @@ C++20 enables a terser syntax.
 #### parameterized tests
 <details><summary></summary>
 
-Tests can be parameterized by type
+Tests can be parameterized with a tuple-like
 
 ```cpp:example/type_parameterized.cpp
 ```
 
-or by value
+or with a range
 
 ```cpp:example/value_parameterized.cpp
 ```
 
-If parameters are defined as a static constant, `param_ref` may enable
-compile-time tests.
+If parameters are defined as a static constant, `constexr_params` and
+`param_ref` can be used to define compile-time tests.
 
+```cpp:example/constexpr_params_parameterized.cpp
+```
 ```cpp:example/param_ref_parameterized.cpp
 ```
 
@@ -143,4 +145,4 @@ Check that abort is called (e.g. in a function precondition).
 </details>
 
 [^1]: The default printer uses `std::cout` and `skytest::aborts` calls `fork`.
-[^2]: https://en.cppreference.com/w/cpp/named_req/LiteralType
+[^2]: https://en.cppreference.com/w/cpp/named_req/LiteralType

src/test_param.hpp

@@ -342,9 +342,32 @@ inline constexpr auto param = param_t<Params>{};
 template <class... Ts>
 inline constexpr auto types = param_ref<detail::type_params<Ts...>>;
 
+template <auto... Values>
+struct constexpr_params_t
+{
+  template <std::size_t I>
+  friend constexpr auto get(constexpr_params_t) -> auto
+  {
+    return std::get<I>(std::tuple{Values...});
+  }
+};
+
+template <auto... Values>
+inline constexpr auto constexpr_params_instance =
+    constexpr_params_t<Values...>{};
+
+template <auto... Values>
+inline constexpr auto constexpr_params =
+    param_ref<constexpr_params_instance<Values...>>;
+
 }  // namespace skytest
 
 template <class... Args>
 struct std::tuple_size<::skytest::detail::type_list<Args...>>
     : ::std::integral_constant<std::size_t, sizeof...(Args)>
 {};
+
+template <auto... Values>
+struct std::tuple_size<skytest::constexpr_params_t<Values...>>
+    : std::integral_constant<std::size_t, sizeof...(Values)>
+{};

test/BUILD.bazel

@@ -295,7 +295,9 @@ skytest_test(
     stdout = [
         "test1.*CONSTEXPR",
         "test2.*CONSTEXPR",
-        "all tests passed.*2 tests",
+        "test3.*CONSTEXPR",
+        "test3.*CONSTEXPR",
+        "all tests passed.*4 tests",
     ],
 )
 

test/requires_constexpr_test.cpp

@@ -1,8 +1,11 @@
 #include "skytest/skytest.hpp"
 
+#include <type_traits>
+
 auto main() -> int
 {
   using namespace ::skytest::literals;
+  using ::skytest::constexpr_params;
   using ::skytest::eq;
   using ::skytest::expect;
   using ::skytest::types;
@@ -13,4 +16,8 @@ auto main() -> int
     using T = typename decltype(param)::type;
     return expect(eq(0, T{}));
   };
+
+  "test3"_ctest * constexpr_params<1, 2U> = [](auto value) {
+    return expect(eq(std::is_same_v<int, decltype(value)> ? 1 : 2, value));
+  };
 }