Rename matchers to be more google-test like.

test/optional_stream_test.cxx

@@ -12,15 +12,15 @@
 
 using ::testing::Eq;
 
-MATCHER(Absent, "") {
+MATCHER(IsNone, "") {
   return !arg.has_value();
 }
 
-MATCHER(Present, "") {
+MATCHER(NotNone, "") {
   return arg.has_value();
 }
 
-MATCHER_P(OptionalIs, value, "") {
+MATCHER_P(Optional, value, "") {
   return arg.has_value() && *arg == value;
 }
 
@@ -29,7 +29,7 @@ TEST(OptionalStreamTest, processes_real) {
   auto plus2 = [](int i) { return i+2; };
   std::optional<int> out = strm.map(plus2);
   
-  EXPECT_THAT(out, Present());
+  EXPECT_THAT(out, NotNone());
   EXPECT_THAT(*out, Eq(7));
 }
 
@@ -39,7 +39,7 @@ TEST(OptionalStreamTest, NoOpWhenUsedOnNullOpts) {
   std::optional<int> out;
   
   EXPECT_NO_THROW(out = strm.map(fail));
-  EXPECT_THAT(out, Absent());
+  EXPECT_THAT(out, IsNone());
 }
 
 TEST(OptionalStreamTest, FlatmapFunctionCanProduceNullOpt) {
@@ -50,7 +50,7 @@ TEST(OptionalStreamTest, FlatmapFunctionCanProduceNullOpt) {
   std::optional<int> out;
   
   EXPECT_NO_THROW(out = strm.flatmap(discard_odd));
-  EXPECT_THAT(out, Absent());
+  EXPECT_THAT(out, IsNone());
 }
 
 TEST(OptionalStreamTest, FlatmapFunctionCanProduceRealValues) {
@@ -61,6 +61,6 @@ TEST(OptionalStreamTest, FlatmapFunctionCanProduceRealValues) {
   std::optional<int> out;
   
   EXPECT_NO_THROW(out = strm.flatmap(discard_odd));
-  EXPECT_THAT(out, Present());
-  EXPECT_THAT(out, OptionalIs(6));
+  EXPECT_THAT(out, NotNone());
+  EXPECT_THAT(out, Optional(6));
 }