While reviewing D57058, Louis had some questions about the existing span constructor tests. They were not testing the stuff that they said they were. Updated the tests to test what they should have been doing

llvm-svn: 351887

2 files changed, 69 insertions, 36 deletions

diff --git a/libcxx/test/std/containers/views/span.cons/container.fail.cpp b/libcxx/test/std/containers/views/span.cons/container.fail.cpp
index 202e6848c10..cfffa57a1e3 100644
--- a/libcxx/test/std/containers/views/span.cons/container.fail.cpp
+++ b/libcxx/test/std/containers/views/span.cons/container.fail.cpp
@@ -26,9 +26,10 @@
 
 #include <span>
 #include <cassert>
-#include <list>
-#include <forward_list>
 #include <deque>
+#include <forward_list>
+#include <list>
+#include <vector>
 
 #include "test_macros.h"
 
@@ -65,52 +66,67 @@ private:
 int main ()
 {
 
-//  Missing size and/or data
+//  Making non-const spans from const sources (a temporary binds to `const &`)
     {
     std::span<int>    s1{IsAContainer<int>()};          // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<int, 0> s2{IsAContainer<int>()};          // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
-    std::span<int>    s3{NotAContainerNoData<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<int, 0> s4{NotAContainerNoData<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
-    std::span<int>    s5{NotAContainerNoSize<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<int, 0> s6{NotAContainerNoSize<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
-    std::span<int>    s7{NotAContainerPrivate<int>()};  // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<int, 0> s8{NotAContainerPrivate<int>()};  // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
+    std::span<int, 0> s2{IsAContainer<int>()};          // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}} 
+    std::span<int>    s3{std::vector<int>()};           // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
+    std::span<int, 0> s4{std::vector<int>()};           // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}} 
+    }
+
+//  Missing size and/or data
+    {
+    std::span<const int>    s1{NotAContainerNoData<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<const int, 0> s2{NotAContainerNoData<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<const int, 0>'}}
+    std::span<const int>    s3{NotAContainerNoSize<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<const int, 0> s4{NotAContainerNoSize<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<const int, 0>'}}
+    std::span<const int>    s5{NotAContainerPrivate<int>()};  // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<const int, 0> s6{NotAContainerPrivate<int>()};  // expected-error {{no matching constructor for initialization of 'std::span<const int, 0>'}}
 
 //  Again with the standard containers
-    std::span<int>    s11{std::deque<int>()};           // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<int, 0> s12{std::deque<int>()};           // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
-    std::span<int>    s13{std::list<int>()};            // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<int, 0> s14{std::list<int>()};            // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
-    std::span<int>    s15{std::forward_list<int>()};    // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<int, 0> s16{std::forward_list<int>()};    // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
+    std::span<const int>    s11{std::deque<int>()};           // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<const int, 0> s12{std::deque<int>()};           // expected-error {{no matching constructor for initialization of 'std::span<const int, 0>'}}
+    std::span<const int>    s13{std::list<int>()};            // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<const int, 0> s14{std::list<int>()};            // expected-error {{no matching constructor for initialization of 'std::span<const int, 0>'}}
+    std::span<const int>    s15{std::forward_list<int>()};    // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<const int, 0> s16{std::forward_list<int>()};    // expected-error {{no matching constructor for initialization of 'std::span<const int, 0>'}}
     }
 
 //  Not the same type
     {
-    std::span<float>    s1{IsAContainer<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<float>'}}
-    std::span<float, 0> s2{IsAContainer<int>()};   // expected-error {{no matching constructor for initialization of 'std::span<float, 0>'}}
+    IsAContainer<int> c;
+    std::span<float>    s1{c};   // expected-error {{no matching constructor for initialization of 'std::span<float>'}}
+    std::span<float, 0> s2{c};   // expected-error {{no matching constructor for initialization of 'std::span<float, 0>'}}
     }
 
 //  CV wrong (dynamically sized)
     {
-    std::span<               int> s1{IsAContainer<const          int>()};   // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<               int> s2{IsAContainer<      volatile int>()};   // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<               int> s3{IsAContainer<const volatile int>()};   // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
-    std::span<const          int> s4{IsAContainer<      volatile int>()};   // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
-    std::span<const          int> s5{IsAContainer<const volatile int>()};   // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
-    std::span<      volatile int> s6{IsAContainer<const          int>()};   // expected-error {{no matching constructor for initialization of 'std::span<volatile int>'}}
-    std::span<      volatile int> s7{IsAContainer<const volatile int>()};   // expected-error {{no matching constructor for initialization of 'std::span<volatile int>'}}
+    IsAContainer<const          int> c;
+    IsAContainer<const volatile int> cv;
+    IsAContainer<      volatile int> v;
+    
+    std::span<               int> s1{c};    // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
+    std::span<               int> s2{v};    // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
+    std::span<               int> s3{cv};   // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
+    std::span<const          int> s4{v};    // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<const          int> s5{cv};   // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
+    std::span<      volatile int> s6{c};    // expected-error {{no matching constructor for initialization of 'std::span<volatile int>'}}
+    std::span<      volatile int> s7{cv};   // expected-error {{no matching constructor for initialization of 'std::span<volatile int>'}}
     }
 
 //  CV wrong (statically sized)
     {
-    std::span<               int,1> s1{IsAContainer<const          int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
-    std::span<               int,1> s2{IsAContainer<      volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
-    std::span<               int,1> s3{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
-    std::span<const          int,1> s4{IsAContainer<      volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<const int, 1>'}}
-    std::span<const          int,1> s5{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<const int, 1>'}}
-    std::span<      volatile int,1> s6{IsAContainer<const          int>()}; // expected-error {{no matching constructor for initialization of 'std::span<volatile int, 1>'}}
-    std::span<      volatile int,1> s7{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<volatile int, 1>'}}
+    IsAContainer<const          int> c;
+    IsAContainer<const volatile int> cv;
+    IsAContainer<      volatile int> v;
+
+    std::span<               int,1> s1{c};  // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
+    std::span<               int,1> s2{v};  // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
+    std::span<               int,1> s3{cv}; // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
+    std::span<const          int,1> s4{v};  // expected-error {{no matching constructor for initialization of 'std::span<const int, 1>'}}
+    std::span<const          int,1> s5{cv}; // expected-error {{no matching constructor for initialization of 'std::span<const int, 1>'}}
+    std::span<      volatile int,1> s6{c};  // expected-error {{no matching constructor for initialization of 'std::span<volatile int, 1>'}}
+    std::span<      volatile int,1> s7{cv}; // expected-error {{no matching constructor for initialization of 'std::span<volatile int, 1>'}}
     }
 
 }
diff --git a/libcxx/test/std/containers/views/span.cons/container.pass.cpp b/libcxx/test/std/containers/views/span.cons/container.pass.cpp
index 8bd5f613d53..4e9001bff8d 100644
--- a/libcxx/test/std/containers/views/span.cons/container.pass.cpp
+++ b/libcxx/test/std/containers/views/span.cons/container.pass.cpp
@@ -73,6 +73,18 @@ void checkCV()
     std::span<      volatile int,3> s3{v};  // a span<      volatile int> pointing at const int.
     std::span<const volatile int,3> s4{v};  // a span<const volatile int> pointing at int.
     }
+
+//  Constructing a const view from a temporary
+    {
+    std::span<const int>    s1{IsAContainer<int>()};
+    std::span<const int, 0> s2{IsAContainer<int>()};
+    std::span<const int>    s3{std::vector<int>()};
+    std::span<const int, 0> s4{std::vector<int>()};
+    (void) s1;
+    (void) s2;
+    (void) s3;
+    (void) s4;
+    }
 }
 
 
@@ -92,10 +104,15 @@ template <typename T>
 void testRuntimeSpan()
 {
     IsAContainer<T> val{};
-    std::span<const T>    s1{val};
-    std::span<const T, 1> s2{val};
-    assert(s1.data() == val.getV() && s1.size() == 1);
-    assert(s2.data() == val.getV() && s2.size() == 1);
+    const IsAContainer<T> cVal;
+    std::span<T>          s1{val};
+    std::span<const T>    s2{cVal};
+    std::span<T, 1>       s3{val};
+    std::span<const T, 1> s4{cVal};
+    assert(s1.data() == val.getV()  && s1.size() == 1);
+    assert(s2.data() == cVal.getV() && s2.size() == 1);
+    assert(s3.data() == val.getV()  && s3.size() == 1);
+    assert(s4.data() == cVal.getV() && s4.size() == 1);
 }
 
 struct A{};