Add pmr allocator examples

examples/src/pmr_allocator_examples.cpp

@@ -0,0 +1,158 @@
+#include <jsoncons/json.hpp>
+#include <memory_resource> 
+#include <cassert>
+#include <jsoncons/json.hpp>
+#include <memory_resource> 
+#include <cassert>
+
+void propagtion()
+{
+    char buffer[1024];
+    std::pmr::monotonic_buffer_resource pool{ std::data(buffer), std::size(buffer) };
+    std::pmr::polymorphic_allocator<char> alloc(&pool);
+
+    std::string key = "key too long for short string";
+    std::string value = "string too long for short string";
+
+    jsoncons::pmr::json j{ jsoncons::json_object_arg, alloc };
+    assert(j.get_allocator().resource() == &pool);
+
+    j.try_emplace(key, value);
+
+    auto it = std::search(std::begin(buffer), std::end(buffer), key.begin(), key.end());
+    assert(it != std::end(buffer));
+    it = std::search(std::begin(buffer), std::end(buffer), value.begin(), value.end());
+    assert(it != std::end(buffer));
+}
+
+void copy_construction()
+{
+    char buffer[1024];
+    std::pmr::monotonic_buffer_resource pool{ std::data(buffer), std::size(buffer) };
+    std::pmr::polymorphic_allocator<char> alloc(&pool);
+
+    jsoncons::pmr::json j{ "String too long for short string", alloc };
+    assert(j.is_string());
+    assert(j.get_allocator().resource() == &pool);
+
+    jsoncons::pmr::json j1(j);
+    assert(j1 == j);
+    assert(j1.get_allocator() == std::allocator_traits<std::pmr::polymorphic_allocator<char>>::
+        select_on_container_copy_construction(j.get_allocator()));
+    assert(j1.get_allocator() == std::pmr::polymorphic_allocator<char>{}); // expected result for pmr allocators
+}
+
+void allocator_extended_copy_construction() // extended copy
+{
+    char buffer[1024];
+    std::pmr::monotonic_buffer_resource pool{ std::data(buffer), std::size(buffer) };
+    std::pmr::polymorphic_allocator<char> alloc(&pool);
+
+    char buffer1[1024];
+    std::pmr::monotonic_buffer_resource pool1{ std::data(buffer1), std::size(buffer1) };
+    std::pmr::polymorphic_allocator<char> alloc1(&pool1);
+
+    jsoncons::pmr::json j{ "String too long for short string", alloc };
+    assert(j.is_string());
+    assert(j.get_allocator().resource() == &pool);
+
+    jsoncons::pmr::json j1(j, alloc1);
+    assert(j1 == j);
+    assert(j1.get_allocator().resource() == &pool1);
+}
+
+void move_construction() // move
+{
+    char buffer[1024];
+    std::pmr::monotonic_buffer_resource pool{ std::data(buffer), std::size(buffer) };
+    std::pmr::polymorphic_allocator<char> alloc(&pool);
+
+    jsoncons::pmr::json j{ "String too long for short string", alloc};
+    assert(j.is_string());
+    assert(j.get_allocator().resource() == &pool);
+
+    jsoncons::pmr::json j1(std::move(j));
+    assert(j1.is_string());
+    assert(j1.get_allocator().resource() == &pool);
+    assert(j.is_null());
+}
+
+void allocator_extended_move_construction() // move
+{
+    char buffer[1024];
+    std::pmr::monotonic_buffer_resource pool{ std::data(buffer), std::size(buffer) };
+    std::pmr::polymorphic_allocator<char> alloc(&pool);
+
+    char buffer1[1024];
+    std::pmr::monotonic_buffer_resource pool1{ std::data(buffer1), std::size(buffer1) };
+    std::pmr::polymorphic_allocator<char> alloc1(&pool1);
+
+    jsoncons::pmr::json j{ "String too long for short string", alloc };
+    assert(j.is_string());
+    assert(j.get_allocator().resource() == &pool);
+
+    jsoncons::pmr::json j1(std::move(j), alloc1);
+    assert(j1.is_string());
+    assert(j1.get_allocator().resource() == &pool1);
+}
+
+void copy_assignment() // assignment
+{
+    char buffer[1024];
+    std::pmr::monotonic_buffer_resource pool{ std::data(buffer), std::size(buffer) };
+    std::pmr::polymorphic_allocator<char> alloc(&pool);
+
+    char buffer1[1024];
+    std::pmr::monotonic_buffer_resource pool1{ std::data(buffer1), std::size(buffer1) };
+    std::pmr::polymorphic_allocator<char> alloc1(&pool1);
+
+    jsoncons::pmr::json j{ "String too long for short string", alloc };
+    assert(j.is_string());
+    assert(j.get_allocator().resource() == &pool);
+
+    // copy long string to number
+    jsoncons::pmr::json j1{10};
+    j1 = j;
+    assert(j1.is_string());
+    assert(j1.get_allocator() == std::allocator_traits<std::pmr::polymorphic_allocator<char>>::
+        select_on_container_copy_construction(j.get_allocator()));
+    assert(j1.get_allocator() == std::pmr::polymorphic_allocator<char>{});
+
+    // copy long string to array
+    jsoncons::pmr::json j2{ jsoncons::json_array_arg, {1,2,3,4}, 
+        jsoncons::semantic_tag::none, alloc1};
+    j2 = j;
+    assert(j2.is_string());
+    assert(j2.get_allocator().resource() == &pool1);
+}
+
+void move_assignment() // assignment
+{
+    char buffer[1024];
+    std::pmr::monotonic_buffer_resource pool{ std::data(buffer), std::size(buffer) };
+    std::pmr::polymorphic_allocator<char> alloc(&pool);
+
+    jsoncons::pmr::json j{ "String too long for short string", alloc };
+    assert(j.is_string());
+    assert(j.get_allocator().resource() == &pool);
+
+    jsoncons::pmr::json j1{ 10 };
+    assert(j1.is_number());
+
+    j1 = std::move(j);
+    assert(j1.is_string());
+    assert(j1.get_allocator().resource() == &pool);
+    assert(j.is_number());
+}
+
+int main()
+{
+    propagtion();
+    copy_construction();
+    allocator_extended_copy_construction();
+    move_construction();
+    allocator_extended_move_construction();
+    copy_assignment();
+    move_assignment();
+}
+