minor: don't use braced init of stdx::string_view

GCC 7 issues an annoying diagnostic when building with -Wconversion
that we would prefer not to raise. Since initialization with ()
works just as weil, use that.

Author: acmorrow

src/bsoncxx/test/bson_builder.cpp

@@ -677,7 +677,7 @@ TEST_CASE("document core builder ownership", "[bsoncxx::builder::core]") {
 
     SECTION("when passing a stdx::string_view, ownership handled by caller") {
         std::string key{"sabich"};
-        stdx::string_view key_view{key};
+        stdx::string_view key_view(key);
         b.key_view(key_view);
         b.append(1);
     }

src/bsoncxx/test/view_or_value.cpp

@@ -187,7 +187,7 @@ TEST_CASE("string::document::view_or_value", "[bsoncxx::string::view_or_value]")
 
     SECTION("can be constructed with a stdx::string_view") {
         std::string name{"Mike"};
-        stdx::string_view name_view{name};
+        stdx::string_view name_view(name);
         string::view_or_value mike{name_view};
 
         SECTION("is non-owning") {

src/mongocxx/test/client.cpp

@@ -251,7 +251,7 @@ TEST_CASE("integration tests for client metadata handshake feature") {
             auto op_view = it.get_document().view();
 
             if (!op_view["appName"] ||
-                op_view["appName"].get_utf8().value != stdx::string_view{app_name}) {
+                op_view["appName"].get_utf8().value != stdx::string_view(app_name)) {
                 continue;
             }
 
@@ -267,7 +267,7 @@ TEST_CASE("integration tests for client metadata handshake feature") {
 
                 REQUIRE(metadata_view["application"]);
                 auto application = metadata_view["application"].get_document();
-                REQUIRE(application.view()["name"].get_utf8().value == stdx::string_view{app_name});
+                REQUIRE(application.view()["name"].get_utf8().value == stdx::string_view(app_name));
 
                 REQUIRE(metadata_view["driver"]);
                 auto driver = metadata_view["driver"].get_document();

src/mongocxx/test/collection.cpp

@@ -128,17 +128,17 @@ TEST_CASE("collection renaming", "[collection]") {
     coll.insert_one(filter.view());  // Ensure that the collection exists.
     other_coll.insert_one({});
 
-    REQUIRE(coll.name() == stdx::string_view{collname});
+    REQUIRE(coll.name() == stdx::string_view(collname));
 
     std::string new_name{"mongo_cxx_newname"};
     coll.rename(new_name, false);
 
-    REQUIRE(coll.name() == stdx::string_view{new_name});
+    REQUIRE(coll.name() == stdx::string_view(new_name));
 
     REQUIRE(coll.find_one(filter.view(), {}));
 
     coll.rename(other_collname, true);
-    REQUIRE(coll.name() == stdx::string_view{other_collname});
+    REQUIRE(coll.name() == stdx::string_view(other_collname));
     REQUIRE(coll.find_one(filter.view(), {}));
 
     coll.drop();
@@ -2266,7 +2266,7 @@ TEST_CASE("create_index tests", "[collection]") {
         options.name(indexName);
 
         auto response = coll.create_index(index.view(), options);
-        REQUIRE(response.view()["name"].get_utf8().value == bsoncxx::stdx::string_view{indexName});
+        REQUIRE(response.view()["name"].get_utf8().value == bsoncxx::stdx::string_view(indexName));
 
         find_index_and_validate(coll, indexName);
 
@@ -2423,7 +2423,7 @@ TEST_CASE("list_indexes", "[collection]") {
         auto name = index["name"].get_utf8();
 
         for (auto&& expected : expected_names) {
-            if (bsoncxx::stdx::string_view{expected} == name.value) {
+            if (bsoncxx::stdx::string_view(expected) == name.value) {
                 found++;
                 if (expected == "a_1") {
                     REQUIRE(index["unique"]);

src/mongocxx/test/gridfs/bucket.cpp

@@ -63,7 +63,7 @@ void validate_gridfs_file(database db,
             expected_contents.size());
     REQUIRE(files_doc->view()["chunkSize"].get_int32().value == expected_chunk_size);
     REQUIRE(files_doc->view()["filename"].get_utf8().value ==
-            stdx::string_view{expected_file_name});
+            stdx::string_view(expected_file_name));
 
     std::int32_t index = 0;
 
@@ -118,7 +118,7 @@ void validate_gridfs_file(
     REQUIRE(static_cast<std::size_t>(files_doc->view()["chunkSize"].get_int32().value) ==
             expected_chunk_size);
     REQUIRE(files_doc->view()["filename"].get_utf8().value ==
-            stdx::string_view{expected_file_name});
+            stdx::string_view(expected_file_name));
 
     std::size_t i = 0;
 

src/mongocxx/test/index_view.cpp

@@ -210,7 +210,7 @@ TEST_CASE("create_many", "[index_view]") {
             auto name = index["name"].get_utf8();
 
             for (auto expected : expected_names) {
-                if (stdx::string_view{expected} == name.value) {
+                if (stdx::string_view(expected) == name.value) {
                     found++;
                 }
             }

src/mongocxx/test/result/gridfs/upload.cpp

@@ -57,7 +57,7 @@ TEST_CASE("result::gridfs::upload owns id", "[result::gridfs::upload]") {
 
     // Because result::gridfs::upload owns its id, we should still be able to correctly read new
     // value for the id.
-    REQUIRE(res.id().get_utf8().value == stdx::string_view{bar});
+    REQUIRE(res.id().get_utf8().value == stdx::string_view(bar));
 }
 
 TEST_CASE("result::gridfs::upload equals", "[result::gridfs::upload]") {