Math: fix tweakable Angle parsers to compile with negative literals.

The result of e.g. -15.0_degf is not Deg, but rather
Math::Unit<Math::Deg, Float>, and those didn't have a corresponding
TweakableParser defined. Now they do.

Funny how I didn't run into this until now.

doc/changelog.dox

@@ -737,6 +737,8 @@ See also:
     off-by-one on desktop GLSL < 330.
 -   Fixed assertions related to OpenGL driver workarounds when the proprietary
     AMDGPU PRO drivers are used on Linux
+-   Fixed @relativeref{Corrade,Utility::Tweakable} parsers to compile with
+    negative @ref Math::Angle literals such as @cpp _(-15.0_degf) @ce
 -   Fixed an assertion when using @ref MeshTools::removeDuplicates() on an
     interleaved @ref Trade::MeshData that included padding at the beginning or
     end of each vertex

src/Magnum/Math/Angle.h

@@ -270,6 +270,11 @@ template<> struct MAGNUM_EXPORT TweakableParser<Magnum::Math::Deg<Magnum::Float>
     static std::pair<TweakableState, Magnum::Math::Deg<Magnum::Float>> parse(Containers::StringView value);
 };
 
+#ifndef DOXYGEN_GENERATING_OUTPUT
+/* Needed to parse e.g. -1.0_degf, which is the base class type */
+template<> struct TweakableParser<Magnum::Math::Unit<Magnum::Math::Deg, Magnum::Float>>: TweakableParser<Magnum::Math::Deg<Magnum::Float>> {};
+#endif
+
 /**
 @tweakableliteral{Magnum::Math::Deg}
 
@@ -283,6 +288,11 @@ template<> struct MAGNUM_EXPORT TweakableParser<Magnum::Math::Deg<Magnum::Double
     static std::pair<TweakableState, Magnum::Math::Deg<Magnum::Double>> parse(Containers::StringView value);
 };
 
+#ifndef DOXYGEN_GENERATING_OUTPUT
+/* Needed to parse e.g. -1.0_deg, which is the base class type */
+template<> struct TweakableParser<Magnum::Math::Unit<Magnum::Math::Deg, Magnum::Double>>: TweakableParser<Magnum::Math::Deg<Magnum::Double>> {};
+#endif
+
 /**
 @tweakableliteral{Magnum::Math::Rad}
 
@@ -296,6 +306,11 @@ template<> struct MAGNUM_EXPORT TweakableParser<Magnum::Math::Rad<Magnum::Float>
     static std::pair<TweakableState, Magnum::Math::Rad<Magnum::Float>> parse(Containers::StringView value);
 };
 
+#ifndef DOXYGEN_GENERATING_OUTPUT
+/* Needed to parse e.g. -1.0_radf, which is the base class type */
+template<> struct TweakableParser<Magnum::Math::Unit<Magnum::Math::Rad, Magnum::Float>>: TweakableParser<Magnum::Math::Rad<Magnum::Float>> {};
+#endif
+
 /**
 @tweakableliteral{Magnum::Math::Rad}
 
@@ -308,6 +323,11 @@ template<> struct MAGNUM_EXPORT TweakableParser<Magnum::Math::Rad<Magnum::Double
     /** @brief Parse the value */
     static std::pair<TweakableState, Magnum::Math::Rad<Magnum::Double>> parse(Containers::StringView value);
 };
+
+#ifndef DOXYGEN_GENERATING_OUTPUT
+/* Needed to parse e.g. -1.0_rad, which is the base class type */
+template<> struct TweakableParser<Magnum::Math::Unit<Magnum::Math::Rad, Magnum::Double>>: TweakableParser<Magnum::Math::Rad<Magnum::Double>> {};
+#endif
 #endif
 
 }}

src/Magnum/Math/Test/AngleTest.cpp

@@ -102,18 +102,34 @@ template<> struct TweakableTraits<Deg> {
     static const char* name() { return "Deg"; }
     static const char* literal() { return "degf"; }
 };
+template<> struct TweakableTraits<Unit<Math::Deg, Float>> {
+    static const char* name() { return "Unit<Deg, Float>"; }
+    static const char* literal() { return "degf"; }
+};
 template<> struct TweakableTraits<Degd> {
     static const char* name() { return "Degd"; }
     static const char* literal() { return "deg"; }
 };
+template<> struct TweakableTraits<Unit<Math::Deg, Double>> {
+    static const char* name() { return "Unit<Deg, Double>"; }
+    static const char* literal() { return "deg"; }
+};
 template<> struct TweakableTraits<Rad> {
     static const char* name() { return "Rad"; }
     static const char* literal() { return "radf"; }
 };
+template<> struct TweakableTraits<Unit<Math::Rad, Float>> {
+    static const char* name() { return "Unit<Rad, Float>"; }
+    static const char* literal() { return "radf"; }
+};
 template<> struct TweakableTraits<Radd> {
     static const char* name() { return "Radd"; }
     static const char* literal() { return "rad"; }
 };
+template<> struct TweakableTraits<Unit<Math::Rad, Double>> {
+    static const char* name() { return "Unit<Rad, Double>"; }
+    static const char* literal() { return "rad"; }
+};
 #endif
 
 AngleTest::AngleTest() {
@@ -134,16 +150,24 @@ AngleTest::AngleTest() {
     #if defined(DOXYGEN_GENERATING_OUTPUT) || defined(CORRADE_TARGET_UNIX) || (defined(CORRADE_TARGET_WINDOWS) && !defined(CORRADE_TARGET_WINDOWS_RT)) || defined(CORRADE_TARGET_EMSCRIPTEN)
     addInstancedTests<AngleTest>({
         &AngleTest::tweakable<Deg>,
+        &AngleTest::tweakable<Unit<Math::Deg, Float>>,
         &AngleTest::tweakable<Degd>,
+        &AngleTest::tweakable<Unit<Math::Deg, Double>>,
         &AngleTest::tweakable<Rad>,
-        &AngleTest::tweakable<Radd>},
+        &AngleTest::tweakable<Unit<Math::Rad, Float>>,
+        &AngleTest::tweakable<Radd>,
+        &AngleTest::tweakable<Unit<Math::Rad, Double>>},
         Corrade::Containers::arraySize(TweakableData));
 
     addInstancedTests<AngleTest>({
         &AngleTest::tweakableError<Deg>,
+        &AngleTest::tweakableError<Unit<Math::Deg, Float>>,
         &AngleTest::tweakableError<Degd>,
+        &AngleTest::tweakableError<Unit<Math::Deg, Double>>,
         &AngleTest::tweakableError<Rad>,
-        &AngleTest::tweakableError<Radd>},
+        &AngleTest::tweakableError<Unit<Math::Rad, Float>>,
+        &AngleTest::tweakableError<Radd>,
+        &AngleTest::tweakableError<Unit<Math::Rad, Double>>},
         Corrade::Containers::arraySize(TweakableErrorData));
     #endif
 }