Vk: parsing Version from configuration.

Needed so I can implement --magnum-vulkan-version.

src/Magnum/Vk/Test/VersionTest.cpp

@@ -25,6 +25,7 @@
 
 #include <sstream>
 #include <Corrade/TestSuite/Tester.h>
+#include <Corrade/Utility/Configuration.h>
 #include <Corrade/Utility/DebugStl.h>
 
 #include "Magnum/Magnum.h"
@@ -41,6 +42,8 @@ struct VersionTest: TestSuite::Tester {
     void comparison();
 
     void debug();
+
+    void configuration();
 };
 
 VersionTest::VersionTest() {
@@ -48,7 +51,9 @@ VersionTest::VersionTest() {
               &VersionTest::packingMagnumVersion,
               &VersionTest::comparison,
 
-              &VersionTest::debug});
+              &VersionTest::debug,
+
+              &VersionTest::configuration});
 }
 
 void VersionTest::packing() {
@@ -128,6 +133,37 @@ void VersionTest::debug() {
     CORRADE_COMPARE(out.str(), "Vulkan 1.2 Vulkan 1.5.789 Vulkan 1023.1023.4095 20.6\n");
 }
 
+void VersionTest::configuration() {
+    Utility::Configuration c;
+
+    /* The ideal thing */
+    c.setValue("version", "1.1");
+    CORRADE_COMPARE(c.value<Version>("version"), Version::Vk11);
+
+    /* Errors */
+    c.setValue("version", "");
+    CORRADE_COMPARE(c.value<Version>("version"), Version::None);
+    c.setValue("version", "1");
+    CORRADE_COMPARE(c.value<Version>("version"), Version::None);
+    c.setValue("version", "1.");
+    CORRADE_COMPARE(c.value<Version>("version"), Version::None);
+    c.setValue("version", ".1");
+    CORRADE_COMPARE(c.value<Version>("version"), Version::None);
+
+    /* Leading spaces */
+    c.setValue("version", "   12.  5");
+    CORRADE_COMPARE(c.value<Version>("version"), version(12, 5));
+
+    /* Trailing spaces */
+    {
+        CORRADE_EXPECT_FAIL("Parsing of trailing spaces not implemented yet.");
+        c.setValue("version", "12  .5");
+        CORRADE_COMPARE(c.value<Version>("version"), version(12, 5));
+        c.setValue("version", "12.5  ");
+        CORRADE_COMPARE(c.value<Version>("version"), version(12, 5));
+    }
+}
+
 }}}}
 
 CORRADE_TEST_MAIN(Magnum::Vk::Test::VersionTest)

src/Magnum/Vk/Version.cpp

@@ -25,6 +25,8 @@
 
 #include "Version.h"
 
+#include <cstdlib>
+#include <Corrade/Containers/StringView.h>
 #include <Corrade/Utility/Debug.h>
 
 #include "Magnum/Vk/Result.h"
@@ -49,3 +51,26 @@ Version enumerateInstanceVersion() {
 }
 
 }}
+
+namespace Corrade { namespace Utility {
+
+using namespace Magnum;
+
+Vk::Version ConfigurationValue<Vk::Version>::fromString(const Containers::StringView& stringValue, ConfigurationValueFlags) {
+    /** @todo trim the string first, once Utility::String::trim() works for
+        views */
+    CORRADE_INTERNAL_ASSERT(stringValue.flags() & Containers::StringViewFlag::NullTerminated);
+
+    char* end;
+    const UnsignedInt major = std::strtoull(stringValue.data(), &end, 10);
+    if(end == stringValue.begin() || end == stringValue.end() || *end != '.' || end + 1 == stringValue.end())
+        return Vk::Version::None;
+
+    const UnsignedInt minor = std::strtoull(end + 1, &end, 10);
+    if(end != stringValue.end())
+        return Vk::Version::None;
+
+    return Vk::version(major, minor);
+}
+
+}}

src/Magnum/Vk/Version.h

@@ -147,4 +147,24 @@ MAGNUM_VK_EXPORT Version enumerateInstanceVersion();
 
 }}
 
+namespace Corrade { namespace Utility {
+
+/**
+@configurationvalue{Magnum::Vk::Version}
+@m_since_latest
+
+Parses a value in the form of `<major>.<minor>`, returns
+@ref Magnum::Vk::Version::None on error. Saving a value to string is not
+implemented.
+*/
+template<> struct ConfigurationValue<Magnum::Vk::Version> {
+    ConfigurationValue() = delete;
+
+    #ifndef DOXYGEN_GENERATING_OUTPUT
+    MAGNUM_VK_EXPORT static Magnum::Vk::Version fromString(const Containers::StringView& stringValue, ConfigurationValueFlags);
+    #endif
+};
+
+}}
+
 #endif