Update 011_memory_ranges_uninitialized_copy_n.cpp

ls-Brynn · web-flow · commit adcb68d1e94a · 2021-07-23T21:57:14.000+08:00
diff --git a/cpp_20/011_memory_ranges_uninitialized_copy_n.cpp b/cpp_20/011_memory_ranges_uninitialized_copy_n.cpp
@@ -1 +1,30 @@
-1
+#include <iomanip>
+#include <iostream>
+#include <memory>
+#include <string>
+ 
+int main()
+{
+    const char* stars[] { "Procyon", "Spica", "Pollux", "Deneb", "Polaris", };
+ 
+    constexpr int n {4};
+    alignas(alignof(std::string)) char out[n * sizeof(std::string)];
+ 
+    try
+    {
+        auto first {reinterpret_cast<std::string*>(out)};
+        auto last {first + n};
+        auto ret {std::ranges::uninitialized_copy_n(std::begin(stars), n, first, last)};
+ 
+        std::cout << "{ ";
+        for (auto it {first}; it != ret.out; ++it)
+            std::cout << std::quoted(*it) << ", ";
+        std::cout << "};\n";
+ 
+        std::ranges::destroy(first, last);
+    }
+    catch(...)
+    {
+        std::cout << "uninitialized_copy_n exception\n";
+    }
+}
