[libcxx] [test] Fix string_view tests.

[STL_MSFT]

Summary

[libcxx] [test] Fix string_view tests.

test/std/strings/string.view/string.view.ops/compare.pointer_size.pass.cpp
Passing -1 to size_t triggers signed/unsigned mismatch warnings because it's
a value-modifying conversion. Add static_cast<size_t> to soothe the compiler.
(This file refers to size_t unqualified.)

test/std/strings/string.view/string.view.ops/substr.pass.cpp
Add <algorithm> for std::min() and <stdexcept> for std::out_of_range.

N4618 21.4.2.4 [string.view.access]/1: "Requires: pos < size()."
/4: "[ Note: Unlike basic_string::operator[], basic_string_view::operator[](size())
has undefined behavior instead of returning charT(). -end note ]"

test/std/strings/string.view/string.view.ops/compare.pointer_size.pass.cpp

int main()
     test("abcde", 0, 6, "abcdefghijklmnopqrst", -15);
     test("abcdefghij", 3, 3, "", 10);
     test("abcdefghij", 3, 3,"abcde", 5);
     test("abcdefghij", 3, 3, "def", 0);
     test("abcdefghij", 0, 4, "abcdefghijklmnopqrst", -10);
     test("abcdefghijklmnopqrst", 5, 5, "", 20);
     test("abcdefghijklmnopqrst", 0, 8, "abcde", 15);
     test("abcdefghijklmnopqrst", 0, 12, "abcdefghij", 10);
-    test("abcdefghijklmnopqrst", 0, -1, "abcdefghijklmnopqrst", 0);
+    test("abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), "abcdefghijklmnopqrst", 0);
     }
 
     {
     test(L"", 0, 0, L"", 0);
     test(L"", 0, 0, L"abcde", -5);
     test(L"", 0, 0, L"abcdefghij", -10);
     test(L"", 0, 0, L"abcdefghijklmnopqrst", -20);
     test(L"abcde", 0, 2, L"", 5);
     test(L"abcde", 0, 6, L"abcde", 0);
     test(L"abcde", 0, 6, L"abcdefghij", -5);
     test(L"abcde", 0, 6, L"abcdefghijklmnopqrst", -15);
     test(L"abcdefghij", 3, 3, L"", 10);
     test(L"abcdefghij", 3, 3, L"abcde", 5);
     test(L"abcdefghij", 3, 3, L"def", 0);
     test(L"abcdefghij", 0, 4, L"abcdefghijklmnopqrst", -10);
     test(L"abcdefghijklmnopqrst", 5, 5, L"", 20);
     test(L"abcdefghijklmnopqrst", 0, 8, L"abcde", 15);
     test(L"abcdefghijklmnopqrst", 0, 12, L"abcdefghij", 10);
-    test(L"abcdefghijklmnopqrst", 0, -1, L"abcdefghijklmnopqrst", 0);
+    test(L"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), L"abcdefghijklmnopqrst", 0);
     }
 
 #if TEST_STD_VER >= 11
     {
     test(U"", 0, 0, U"", 0);
     test(U"", 0, 0, U"abcde", -5);
     test(U"", 0, 0, U"abcdefghij", -10);
     test(U"", 0, 0, U"abcdefghijklmnopqrst", -20);
     test(U"abcde", 0, 2, U"", 5);
     test(U"abcde", 0, 6, U"abcde", 0);
     test(U"abcde", 0, 6, U"abcdefghij", -5);
     test(U"abcde", 0, 6, U"abcdefghijklmnopqrst", -15);
     test(U"abcdefghij", 3, 3, U"", 10);
     test(U"abcdefghij", 3, 3, U"abcde", 5);
     test(U"abcdefghij", 3, 3, U"def", 0);
     test(U"abcdefghij", 0, 4, U"abcdefghijklmnopqrst", -10);
     test(U"abcdefghijklmnopqrst", 5, 5, U"", 20);
     test(U"abcdefghijklmnopqrst", 0, 8, U"abcde", 15);
     test(U"abcdefghijklmnopqrst", 0, 12, U"abcdefghij", 10);
-    test(U"abcdefghijklmnopqrst", 0, -1, U"abcdefghijklmnopqrst", 0);
+    test(U"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), U"abcdefghijklmnopqrst", 0);
     }
 
     {
     test(u"", 0, 0, u"", 0);
     test(u"", 0, 0, u"abcde", -5);
     test(u"", 0, 0, u"abcdefghij", -10);
     test(u"", 0, 0, u"abcdefghijklmnopqrst", -20);
     test(u"abcde", 0, 2, u"", 5);
     test(u"abcde", 0, 6, u"abcde", 0);
     test(u"abcde", 0, 6, u"abcdefghij", -5);
     test(u"abcde", 0, 6, u"abcdefghijklmnopqrst", -15);
     test(u"abcdefghij", 3, 3, u"", 10);
     test(u"abcdefghij", 3, 3, u"abcde", 5);
     test(u"abcdefghij", 3, 3, u"def", 0);
     test(u"abcdefghij", 0, 4, u"abcdefghijklmnopqrst", -10);
     test(u"abcdefghijklmnopqrst", 5, 5, u"", 20);
     test(u"abcdefghijklmnopqrst", 0, 8, u"abcde", 15);
     test(u"abcdefghijklmnopqrst", 0, 12, u"abcdefghij", 10);
-    test(u"abcdefghijklmnopqrst", 0, -1, u"abcdefghijklmnopqrst", 0);
+    test(u"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), u"abcdefghijklmnopqrst", 0);
     }
 #endif
 
 #if TEST_STD_VER > 11
     {
     typedef std::basic_string_view<char, constexpr_char_traits<char>> SV;
     constexpr SV  sv1;
     constexpr SV  sv2 { "abcde", 5 };
     static_assert ( sv1.compare(0, 0, "") == 0, "" );
     static_assert ( sv1.compare(0, 0, "abcde") == -1, "" );
     static_assert ( sv2.compare(0, 2, "") == 1, "" );
     static_assert ( sv2.compare(0, 6, "abcde") == 0, "" );
     }
 #endif
 }

test/std/strings/string.view/string.view.ops/substr.pass.cpp

 
 // constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
 
 // Throws: out_of_range if pos > size().
 // Effects: Determines the effective length rlen of the string to reference as the smaller of n and size() - pos.
 // Returns: basic_string_view(data()+pos, rlen).
 
 #include <string_view>
+#include <algorithm>
+#include <stdexcept>
 #include <cassert>
 
 #include "test_macros.h"
 
 template<typename CharT>
 void test1(std::basic_string_view<CharT> sv, size_t n, size_t pos) {
     std::basic_string_view<CharT> sv1;
 #ifdef TEST_HAS_NO_EXCEPTIONS
     if (pos > sv.size())
         return ;  // would throw if exceptions were enabled
     sv1 = sv.substr(pos, n);
 #else
     try {
         sv1 = sv.substr(pos, n);
         assert(pos <= sv.size());
     }
     catch (const std::out_of_range&) {
         assert(pos > sv.size());
         return ;
     }
 #endif
     const size_t rlen = std::min(n, sv.size() - pos);
     assert (sv1.size() == rlen);
-    for (size_t i = 0; i <= rlen; ++i)
+    for (size_t i = 0; i < rlen; ++i)
         assert(sv[pos+i] == sv1[i]);
 }
 
 
 template<typename CharT>
 void test ( const CharT *s ) {
     typedef std::basic_string_view<CharT> string_view_t;