test/cfg: Improved testing of std.cfg about std::stod().

cfg/std.cfg

@@ -3501,6 +3501,19 @@
     </arg>
     <arg nr="2"/>
   </function>
+  <!-- double stod (const string&  str, size_t* idx = 0); -->
+  <!-- double stod (const wstring& str, size_t* idx = 0); -->
+  <function name="std::stod">
+    <use-retval/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+    <arg nr="2">
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- size_t mbrtowc(wchar_t* pwc, const char* pmb, size_t max, mbstate_t* ps); -->
   <function name="mbrtowc,std::mbrtowc">
     <noreturn>false</noreturn>

test/cfg/std.cpp

@@ -2489,6 +2489,17 @@ void uninivar_wcstof(void)
     (void)std::wcstold(s,endp);
 }
 
+void uninivar_stod(void)
+{
+    std::string str;
+    std::wstring wstr;
+    size_t* idx;
+    // cppcheck-suppress uninitvar
+    (void)std::stod(str,idx);
+    // cppcheck-suppress uninitvar
+    (void)std::stod(wstr,idx);
+}
+
 void uninivar_mbrtowc(void)
 {
     wchar_t* pwc;