Utils: Add std::string conversion constructor and operator to small string

Change-Id: Ia76d7647fc8d2c9b72bc5bce2e7a6e2c3fcc18cc
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/libs/utils/smallstring.h

@@ -42,6 +42,7 @@
 #include <climits>
 #include <cstring>
 #include <iosfwd>
+#include <string>
 #include <utility>
 
 #pragma push_macro("constexpr")
@@ -127,6 +128,10 @@ public:
         : SmallString(SmallString::fromQString(qString))
     {}
 
+    SmallString(const std::string &stdString)
+        : SmallString(stdString.data(), stdString.size())
+    {}
+
     template<typename BeginIterator,
              typename EndIterator,
              typename = typename std::enable_if<std::is_same<BeginIterator, EndIterator>::value>::type
@@ -216,6 +221,11 @@ public:
         return toQString();
     }
 
+    operator std::string() const
+    {
+        return std::string(data(), size());
+    }
+
     static
     SmallString fromUtf8(const char *characterPointer)
     {

src/libs/utils/smallstringvector.h

@@ -131,6 +131,11 @@ public:
         return clonedVector;
     }
 
+    operator std::vector<std::string>() const
+    {
+        return std::vector<std::string>(begin(), end());
+    }
+
 private:
     std::size_t totalByteSize() const
     {

tests/unit/unittest/smallstringtest.cpp

@@ -319,6 +319,15 @@ TEST(SmallString, RBeginPlusOneIsEqualREndForSmallStringWidthSizeOne)
     ASSERT_THAT(beginPlusOne, Eq(text.rend()));
 }
 
+TEST(SmallString, ConstructorStandardString)
+{
+    std::string stdStringText = "short string";
+
+    auto text = SmallString(stdStringText);
+
+    ASSERT_THAT(text, SmallString("short string"));
+}
+
 TEST(SmallString, ToQString)
 {
     SmallString text("short string");