Add removeprefix and removesuffix to pystring

pystring.cpp

@@ -1071,6 +1071,31 @@ const std::string colon = ":";
         return os.str();
     }
 
+    //////////////////////////////////////////////////////////////////////////////////////////////
+    ///
+    ///
+    std::string removeprefix( const std::string & str, const std::string & prefix )
+    {
+        if (pystring::startswith(str, prefix))
+        {
+            return str.substr(prefix.length());
+        }
+
+        return str;
+    }
+
+    //////////////////////////////////////////////////////////////////////////////////////////////
+    ///
+    ///
+    std::string removesuffix( const std::string & str, const std::string & suffix )
+    {
+        if (pystring::endswith(str, suffix))
+        {
+            return str.substr(0, str.length() - suffix.length());
+        }
+
+        return str;
+    }
 
 
 namespace os

pystring.h

@@ -179,6 +179,18 @@ namespace pystring
     ///
     void partition( const std::string & str, const std::string & sep, std::vector< std::string > & result );
 
+    //////////////////////////////////////////////////////////////////////////////////////////////
+    /// @brief If str starts with prefix return a copy of the string with prefix at the start
+    /// removed otherwise return an unmodified copy of the string.
+    ///
+    std::string removeprefix( const std::string & str, const std::string & prefix );
+
+    //////////////////////////////////////////////////////////////////////////////////////////////
+    /// @brief If str ends with suffix return a copy of the string with suffix at the end removed
+    /// otherwise return an unmodified copy of the string.
+    ///
+    std::string removesuffix( const std::string & str, const std::string & suffix );
+
     //////////////////////////////////////////////////////////////////////////////////////////////
     /// @brief Return a copy of the string with all occurrences of substring old replaced by new. If
     /// the optional argument count is given, only the first count occurrences are replaced.

test.cpp

@@ -94,6 +94,18 @@ PYSTRING_ADD_TEST(pystring, rfind)
     PYSTRING_CHECK_EQUAL(pystring::rfind("abcabcabc", "abc", 6, 8), -1);
 }
 
+PYSTRING_ADD_TEST(pystring, removeprefix)
+{
+    PYSTRING_CHECK_EQUAL(pystring::removeprefix("abcdef", "abc"), "def");
+    PYSTRING_CHECK_EQUAL(pystring::removeprefix("abcdef", "bcd"), "abcdef");
+}
+
+PYSTRING_ADD_TEST(pystring, removesuffix)
+{
+    PYSTRING_CHECK_EQUAL(pystring::removesuffix("abcdef", "def"), "abc");
+    PYSTRING_CHECK_EQUAL(pystring::removesuffix("abcdef", "cde"), "abcdef");
+}
+
 PYSTRING_ADD_TEST(pystring, replace)
 {
     PYSTRING_CHECK_EQUAL(pystring::replace("abcdef", "foo", "bar"), "abcdef");