test: add default constructor for a const value
This fixed a compilation error of the OS X 10.11.6 C++ compiler:
./fmt/test/format-test.cc:1861:16: error: default initialization of an object of const type 'const Answer' without a user-provided default constructor
const Answer const_answer;
^
{}
diff --git a/test/format-test.cc b/test/format-test.cc
index 66d87c2..08828cc 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -1917,7 +1917,7 @@
EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), Answer()));
Answer answer;
EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), answer));
- const Answer const_answer;
+ const Answer const_answer = Answer();
EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), const_answer));
}