More P0202 constexpr-ifying in <algorithm>. This commit handles replace/replace_if/replace_copy/replace_copy_if.

llvm-svn: 322975

4 files changed, 82 insertions, 6 deletions

diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace.pass.cpp
index f6033351ffc..56a744b2c9d 100644
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace.pass.cpp
@@ -13,14 +13,27 @@
 //   requires OutputIterator<Iter, Iter::reference>
 //         && OutputIterator<Iter, const T&>
 //         && HasEqualTo<Iter::value_type, T>
-//   void
+//   constexpr void      // constexpr after C++17
 //   replace(Iter first, Iter last, const T& old_value, const T& new_value);
 
 #include <algorithm>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 
+
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR bool test_constexpr() {
+          int ia[]       = {0, 1, 2, 3, 4};
+    const int expected[] = {0, 1, 5, 3, 4};
+
+    std::replace(std::begin(ia), std::end(ia), 2, 5);
+    return std::equal(std::begin(ia), std::end(ia), std::begin(expected), std::end(expected))
+        ;
+    }
+#endif
+
 template <class Iter>
 void
 test()
@@ -41,4 +54,8 @@ int main()
     test<bidirectional_iterator<int*> >();
     test<random_access_iterator<int*> >();
     test<int*>();
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy.pass.cpp
index 3c4d0e50817..aad7f9f921d 100644
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy.pass.cpp
@@ -13,15 +13,32 @@
 //   requires OutputIterator<OutIter, InIter::reference>
 //         && OutputIterator<OutIter, const T&>
 //         && HasEqualTo<InIter::value_type, T>
-//   OutIter
+//   constexpr OutIter      // constexpr after C++17
 //   replace_copy(InIter first, InIter last, OutIter result, const T& old_value,
 //                                                           const T& new_value);
 
 #include <algorithm>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 
+
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR bool test_constexpr() {
+    int ia[] = {0, 1, 2, 3, 4};
+    int ib[] = {0, 0, 0, 0, 0, 0}; // one bigger
+    const int expected[] = {0, 1, 5, 3, 4};
+
+    auto it = std::replace_copy(std::begin(ia), std::end(ia), std::begin(ib), 2, 5);
+    
+    return it == (std::begin(ib) + std::size(ia))
+        && *it == 0 // don't overwrite the last value in the output array
+        && std::equal(std::begin(ib), it, std::begin(expected), std::end(expected))
+        ;
+    }
+#endif
+
 template <class InIter, class OutIter>
 void
 test()
@@ -69,4 +86,8 @@ int main()
     test<const int*, bidirectional_iterator<int*> >();
     test<const int*, random_access_iterator<int*> >();
     test<const int*, int*>();
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy_if.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy_if.pass.cpp
index f2ffece12e8..6ba74ff07bd 100644
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy_if.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_copy_if.pass.cpp
@@ -14,16 +14,33 @@
 //   requires OutputIterator<OutIter, InIter::reference>
 //         && OutputIterator<OutIter, const T&>
 //         && CopyConstructible<Pred>
-//   OutIter
+//   constexpr OutIter      // constexpr after C++17
 //   replace_copy_if(InIter first, InIter last, OutIter result, Pred pred, const T& new_value);
 
 #include <algorithm>
 #include <functional>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 
-bool equalToTwo(int v) { return v == 2; }
+TEST_CONSTEXPR bool equalToTwo(int v) { return v == 2; }
+
+
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR bool test_constexpr() {
+    int ia[] = {0, 1, 2, 3, 4};
+    int ib[] = {0, 0, 0, 0, 0, 0}; // one bigger
+    const int expected[] = {0, 1, 5, 3, 4};
+
+    auto it = std::replace_copy_if(std::begin(ia), std::end(ia), std::begin(ib), equalToTwo, 5);
+    
+    return it == (std::begin(ib) + std::size(ia))
+        && *it == 0 // don't overwrite the last value in the output array
+        && std::equal(std::begin(ib), it, std::begin(expected), std::end(expected))
+        ;
+    }
+#endif
 
 template <class InIter, class OutIter>
 void
@@ -73,4 +90,8 @@ int main()
     test<const int*, bidirectional_iterator<int*> >();
     test<const int*, random_access_iterator<int*> >();
     test<const int*, int*>();
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_if.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_if.pass.cpp
index ebb2945d7c4..eeff4068740 100644
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_if.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.replace/replace_if.pass.cpp
@@ -13,16 +13,29 @@
 //   requires OutputIterator<Iter, Iter::reference>
 //         && OutputIterator<Iter, const T&>
 //         && CopyConstructible<Pred>
-//   void
+//   constexpr void      // constexpr after C++17
 //   replace_if(Iter first, Iter last, Pred pred, const T& new_value);
 
 #include <algorithm>
 #include <functional>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 
-bool equalToTwo(int v) { return v == 2; }
+TEST_CONSTEXPR bool equalToTwo(int v) { return v == 2; }
+
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR bool test_constexpr() {
+          int ia[]       = {0, 1, 2, 3, 4};
+    const int expected[] = {0, 1, 5, 3, 4};
+
+    std::replace_if(std::begin(ia), std::end(ia), equalToTwo, 5);
+    return std::equal(std::begin(ia), std::end(ia), std::begin(expected), std::end(expected))
+        ;
+    }
+#endif
+
 
 template <class Iter>
 void
@@ -44,4 +57,8 @@ int main()
     test<bidirectional_iterator<int*> >();
     test<random_access_iterator<int*> >();
     test<int*>();
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }