STYLE: Use default member initialization

Converts a default constructor’s member initializers into the new
default member initializers in C++11. Other member initializers that match the
default member initializer are removed. This can reduce repeated code or allow
use of ‘= default’.

SRCDIR=/Users/johnsonhj/src/jsoncpp/ #My local SRC
BLDDIR=/Users/johnsonhj/src/jsoncpp/cmake-build-debug/ #My local BLD

cd /Users/johnsonhj/src/jsoncpp/cmake-build-debug/
run-clang-tidy.py -extra-arg=-D__clang__ -checks=-*,modernize-use-default-member-init  -header-filter=.* -fix

src/test_lib_json/jsontest.cpp

@@ -74,7 +74,7 @@ namespace JsonTest {
 // //////////////////////////////////////////////////////////////////
 
 TestResult::TestResult()
-    : predicateId_(1), lastUsedPredicateId_(0), messageTarget_(nullptr) {
+     {
   // The root predicate has id 0
   rootPredicateNode_.id_ = 0;
   rootPredicateNode_.next_ = nullptr;
@@ -205,7 +205,7 @@ TestResult& TestResult::operator<<(bool value) {
 // class TestCase
 // //////////////////////////////////////////////////////////////////
 
-TestCase::TestCase() : result_(nullptr) {}
+TestCase::TestCase()  {}
 
 TestCase::~TestCase() {}