diff --git a/cfg/std.cfg b/cfg/std.cfg
index c93859efb..4545c5429 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -4023,9 +4023,27 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
       <not-uninit/>
     </arg>
   </function>
+  <function name="std::string::at">
+    <noreturn>false</noreturn>
+    <returnValue type="char"/>
+    <use-retval/>
+    <arg nr="1">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+  </function>
+  <function name="std::string::c_str">
+    <noreturn>false</noreturn>
+    <returnValue type="const char *"/>
+    <use-retval/>
+  </function>
+  <function name="std::string::clear">
+    <noreturn>false</noreturn>
+  </function>
   <function name="std::string::empty">
     <noreturn>false</noreturn>
     <returnValue type="bool"/>
+    <use-retval/>
   </function>
   <!-- size_t find (const string& str, size_t pos = 0) const; -->
   <!-- size_t find (const char* s, size_t pos, size_t n) const; -->
@@ -4047,6 +4065,16 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
       <valid>0:</valid>
     </arg>
   </function>
+  <function name="std::string::length">
+    <noreturn>false</noreturn>
+    <returnValue type="std::size_t"/>
+    <use-retval/>
+  </function>
+  <function name="std::string::size">
+    <noreturn>false</noreturn>
+    <returnValue type="std::size_t"/>
+    <use-retval/>
+  </function>
   <!-- istream& read (char* s, streamsize n); 
        ifstream& read (char* s, streamsize n); -->
   <function name="std::istream::read,std::ifstream::read">
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 672dccd04..ef76f6ae8 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -5001,6 +5001,18 @@ bool ValueType::fromLibraryType(const std::string &typestr, const Settings *sett
         if (platformType->_const_ptr)
             constness = 1;
         return true;
+    } else if (!podtype && (typestr == "size_t" || typestr == "std::size_t")) {
+        originalTypeName = "size_t";
+        sign = ValueType::UNSIGNED;
+        if (settings->sizeof_size_t == settings->sizeof_long)
+            type = ValueType::Type::LONG;
+        else if (settings->sizeof_size_t == settings->sizeof_long_long)
+            type = ValueType::Type::LONGLONG;
+        else if (settings->sizeof_size_t == settings->sizeof_int)
+            type = ValueType::Type::INT;
+        else
+            type = ValueType::Type::UNKNOWN_INT;
+        return true;
     }
 
     return false;