Add support for std::string_view::substr() (#4729)

Author: chrchr-github

cfg/std.cfg

@@ -7369,6 +7369,34 @@ initializer list (7) string& replace (const_iterator i1, const_iterator i2, init
       <valid>0:</valid>
     </arg>
   </function>
+  <!-- https://en.cppreference.com/w/cpp/string/basic_string_view/substr -->
+  <!-- constexpr basic_string_view substr( size_type pos = 0, size_type count = npos ) const; -->
+  <function name="std::string_view::substr">
+    <use-retval/>
+    <returnValue type="std::string_view"/>
+    <noreturn>false</noreturn>
+    <arg nr="1" default="0" direction="in">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+    <arg nr="2" default="0" direction="in">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+  </function>
+  <function name="std::wstring_view::substr">
+    <use-retval/>
+    <returnValue type="std::wstring_view"/>
+    <noreturn>false</noreturn>
+    <arg nr="1" default="0" direction="in">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+    <arg nr="2" default="0" direction="in">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+  </function>
   <!-- default (1) template <class ForwardIterator>                ForwardIterator std::min_element (ForwardIterator first, ForwardIterator last);
         custom (2) template <class ForwardIterator, class Compare> ForwardIterator std::min_element (ForwardIterator first, ForwardIterator last, Compare comp); -->
   <!-- default (1) template <class ForwardIterator>                ForwardIterator std::max_element (ForwardIterator first, ForwardIterator last);

test/cfg/runtests.sh

@@ -27,7 +27,7 @@ CPPCHECK_OPT='--check-library --platform=unix64 --enable=information --enable=st
 
 # Compiler settings
 CXX=g++
-CXX_OPT='-fsyntax-only -std=c++0x -Wno-format -Wno-format-security -Wno-deprecated-declarations'
+CXX_OPT='-fsyntax-only -std=c++17 -Wno-format -Wno-format-security -Wno-deprecated-declarations'
 CC=gcc
 CC_OPT='-Wno-format -Wno-stringop-overread -Wno-nonnull -Wno-implicit-function-declaration -Wno-deprecated-declarations -Wno-format-security -Wno-nonnull -fsyntax-only'
 

test/cfg/std.cpp

@@ -7,6 +7,7 @@
 // No warnings about bad library configuration, unmatched suppressions, etc. exitcode=0
 //
 
+#include <algorithm>
 #include <bitset>
 #include <cassert>
 #include <cctype>
@@ -34,10 +35,10 @@
 #include <iostream>
 #include <istream>
 #include <iterator>
-#include <vector>
-#include <unordered_set>
-#include <algorithm>
 #include <numeric>
+#include <string_view>
+#include <unordered_set>
+#include <vector>
 
 int zerodiv_ldexp()
 {
@@ -4555,4 +4556,10 @@ void addressof(int a)
 {
     // cppcheck-suppress ignoredReturnValue
     std::addressof(a);
+}
+
+void string_view_unused(std::string_view v)
+{
+    // cppcheck-suppress ignoredReturnValue
+    v.substr(1, 3);
 }