[libc++][test] Fix zero-length arrays and copy-pasted lambdas in ranges.contains.pass.cpp

[StephanTLavavej]

• Fix MSVC error C2466: cannot allocate an array of constant size 0
  • MSVC rejects this non-Standard extension. Previous fixes: [libc++][test] Avoid non-Standard zero-length arrays #74183
• Fix MSVC warning C4805: '==': unsafe mix of type 'int' and type 'const bool' in operation
  • AFAICT, these lambdas were copy-pasted, and didn't intend to take and return int here. This part of the test is using vector<bool> for random-access but non-contiguous iterators, and it's checking how many times the projection is invoked, but the projection doesn't need to do anything squirrely, it should otherwise be an identity.
• Fix typos: "continuous" => "contiguous".

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Stephan T. Lavavej (StephanTLavavej)

Changes

• Fix MSVC error C2466: cannot allocate an array of constant size 0
  • MSVC rejects this non-Standard extension. Previous fixes: #74183
• Fix MSVC warning C4805: '==': unsafe mix of type 'int' and type 'const bool' in operation
  • AFAICT, these lambdas were copy-pasted, and didn't intend to take and return int here. This part of the test is using vector<bool> for random-access but non-contiguous iterators, and it's checking how many times the projection is invoked, but the projection doesn't need to do anything squirrely, it should otherwise be an identity.
• Fix typos: "continuous" => "contiguous".

---

Full diff: https://github.com/llvm/llvm-project/pull/79792.diff

1 Files Affected:

• (modified) libcxx/test/std/algorithms/alg.nonmodifying/alg.contains/ranges.contains.pass.cpp (+9-8)

diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.contains/ranges.contains.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.contains/ranges.contains.pass.cpp
index c928698e453013..7b792bb3ac80c6 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.contains/ranges.contains.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.contains/ranges.contains.pass.cpp
@@ -19,6 +19,7 @@
 //     constexpr bool ranges::contains(R&& r, const T& value, Proj proj = {});                 // since C++23
 
 #include <algorithm>
+#include <array>
 #include <cassert>
 #include <list>
 #include <ranges>
@@ -89,8 +90,8 @@ constexpr void test_iterators() {
   }
 
   { // check that an empty range works
-    ValueT a[] = {};
-    auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a)));
+    std::array<ValueT, 0> a = {};
+    auto whole = std::ranges::subrange(Iter(a.data()), Sent(Iter(a.data())));
     {
       bool ret = std::ranges::contains(whole.begin(), whole.end(), 1);
       assert(!ret);
@@ -164,7 +165,7 @@ constexpr bool test() {
     });
   });
 
-  { // count invocations of the projection for continuous iterators
+  { // count invocations of the projection for contiguous iterators
     int a[]              = {1, 9, 0, 13, 25};
     int projection_count = 0;
     {
@@ -215,22 +216,22 @@ constexpr bool test() {
     }
   }
 
-  { // check invocations of the projection for non-continuous iterators
+  { // check invocations of the projection for non-contiguous iterators
     std::vector<bool> whole{false, false, true, false};
     int projection_count = 0;
     {
-      bool ret = std::ranges::contains(whole.begin(), whole.end(), true, [&](int i) {
+      bool ret = std::ranges::contains(whole.begin(), whole.end(), true, [&](bool b) {
         ++projection_count;
-        return i;
+        return b;
       });
       assert(ret);
       assert(projection_count == 3);
       projection_count = 0;
     }
     {
-      bool ret = std::ranges::contains(whole, true, [&](int i) {
+      bool ret = std::ranges::contains(whole, true, [&](bool b) {
         ++projection_count;
-        return i;
+        return b;
       });
       assert(ret);
       assert(projection_count == 3);

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