[libc++] Refactor string unit tests to ease addition of new allocators

While doing this, I also found a few tests that were either clearly
incorrect (e.g. testing the wrong function) or that lacked basic test
coverage like testing std::string itself (e.g. the test was only checking
std::basic_string with a custom allocator). In these cases, I did a few
conservative drive-by changes.

Differential Revision: https://reviews.llvm.org/D140550
Co-authored-by: Brendan Emery <brendan.emery@esrlabs.com>

1 files changed, 22 insertions, 34 deletions

diff --git a/libcxx/test/std/strings/basic.string/string.cons/pointer_alloc.pass.cpp b/libcxx/test/std/strings/basic.string/string.cons/pointer_alloc.pass.cpp
index c7e31f5e64e0..84a29df5b57b 100644
--- a/libcxx/test/std/strings/basic.string/string.cons/pointer_alloc.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.cons/pointer_alloc.pass.cpp
@@ -20,23 +20,22 @@
 #include "test_allocator.h"
 #include "min_allocator.h"
 
-template <class charT>
+template <class Alloc, class charT>
 TEST_CONSTEXPR_CXX20 void test(const charT* s) {
-  typedef std::basic_string<charT, std::char_traits<charT>, test_allocator<charT> > S;
+  typedef std::basic_string<charT, std::char_traits<charT>, Alloc> S;
   typedef typename S::traits_type T;
-  typedef typename S::allocator_type A;
   std::size_t n = T::length(s);
   S s2(s);
   LIBCPP_ASSERT(s2.__invariants());
   assert(s2.size() == n);
   assert(T::compare(s2.data(), s, n) == 0);
-  assert(s2.get_allocator() == A());
+  assert(s2.get_allocator() == Alloc());
   assert(s2.capacity() >= s2.size());
 }
 
-template <class charT, class A>
-TEST_CONSTEXPR_CXX20 void test(const charT* s, const A& a) {
-  typedef std::basic_string<charT, std::char_traits<charT>, A> S;
+template <class Alloc, class charT>
+TEST_CONSTEXPR_CXX20 void test(const charT* s, const Alloc& a) {
+  typedef std::basic_string<charT, std::char_traits<charT>, Alloc> S;
   typedef typename S::traits_type T;
   std::size_t n = T::length(s);
   S s2(s, a);
@@ -47,38 +46,27 @@ TEST_CONSTEXPR_CXX20 void test(const charT* s, const A& a) {
   assert(s2.capacity() >= s2.size());
 }
 
-TEST_CONSTEXPR_CXX20 bool test() {
-  {
-    typedef test_allocator<char> A;
+template <class Alloc>
+TEST_CONSTEXPR_CXX20 void test(const Alloc& a) {
+  test<Alloc>("");
+  test<Alloc>("", Alloc(a));
 
-    test("");
-    test("", A(2));
+  test<Alloc>("1");
+  test<Alloc>("1", Alloc(a));
 
-    test("1");
-    test("1", A(2));
+  test<Alloc>("1234567980");
+  test<Alloc>("1234567980", Alloc(a));
 
-    test("1234567980");
-    test("1234567980", A(2));
+  test<Alloc>("123456798012345679801234567980123456798012345679801234567980");
+  test<Alloc>("123456798012345679801234567980123456798012345679801234567980", Alloc(a));
+}
 
-    test("123456798012345679801234567980123456798012345679801234567980");
-    test("123456798012345679801234567980123456798012345679801234567980", A(2));
-  }
+TEST_CONSTEXPR_CXX20 bool test() {
+  test(std::allocator<char>());
+  test(test_allocator<char>());
+  test(test_allocator<char>(2));
 #if TEST_STD_VER >= 11
-  {
-    typedef min_allocator<char> A;
-
-    test("");
-    test("", A());
-
-    test("1");
-    test("1", A());
-
-    test("1234567980");
-    test("1234567980", A());
-
-    test("123456798012345679801234567980123456798012345679801234567980");
-    test("123456798012345679801234567980123456798012345679801234567980", A());
-  }
+  test(min_allocator<char>());
 #endif
 
   return true;