Add emplace test

CMakeLists.txt

@@ -23,6 +23,7 @@ if(OPTIONAL_ENABLE_TESTS)
                    ${CMAKE_CURRENT_SOURCE_DIR}/tests/relops.cpp
                    ${CMAKE_CURRENT_SOURCE_DIR}/tests/observers.cpp
                    ${CMAKE_CURRENT_SOURCE_DIR}/tests/extensions.cpp
+                   ${CMAKE_CURRENT_SOURCE_DIR}/tests/emplace.cpp
                    ${CMAKE_CURRENT_SOURCE_DIR}/tests/constexpr.cpp
                    ${CMAKE_CURRENT_SOURCE_DIR}/tests/constructors.cpp
                    ${CMAKE_CURRENT_SOURCE_DIR}/tests/assignment.cpp

tests/emplace.cpp

@@ -0,0 +1,13 @@
+#include "catch.hpp"
+#include "optional.hpp"
+#include <utility>
+#include <tuple>
+
+TEST_CASE("Emplace", "[emplace]") {
+    tl::optional<std::pair<std::pair<int,int>, std::pair<double, double>>> i;
+    i.emplace(std::piecewise_construct, std::make_tuple(0,2), std::make_tuple(3,4));
+    REQUIRE(i->first.first == 0);
+    REQUIRE(i->first.second == 2);
+    REQUIRE(i->second.first == 3);
+    REQUIRE(i->second.second == 4);    
+}

tl/optional.hpp

@@ -1258,6 +1258,7 @@ public:
 
     *this = nullopt;
     this->construct(std::forward<Args>(args)...);
+    return value();
   }
 
   /// \group emplace
@@ -1269,6 +1270,7 @@ public:
   emplace(std::initializer_list<U> il, Args &&... args) {
     *this = nullopt;
     this->construct(il, std::forward<Args>(args)...);
+    return value();    
   }
 
   /// Swaps this optional with the other.