Modernize code

* use `using` instead of typdef
* use `collection.empty()` instead of size
* use `auto` if clear
* use `emplace_back` where useful
* use `nullptr` instead of NULL
* use `override` if applicable
* use `explicit` for constructor to avoid implicit conversion

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/Expr/ArrayExprOptimizer.h b/lib/Expr/ArrayExprOptimizer.h
index 7d895a48..40199821 100644
--- a/lib/Expr/ArrayExprOptimizer.h
+++ b/lib/Expr/ArrayExprOptimizer.h
@@ -24,8 +24,8 @@ namespace klee {
 
 enum ArrayOptimizationType { NONE, ALL, INDEX, VALUE };
 
-typedef std::map<const Array *, std::vector<ref<Expr>>> array2idx_ty;
-typedef std::map<ref<Expr>, std::vector<ref<Expr>>> mapIndexOptimizedExpr_ty;
+using array2idx_ty = std::map<const Array *, std::vector<ref<Expr>>>;
+using mapIndexOptimizedExpr_ty = std::map<ref<Expr>, std::vector<ref<Expr>>>;
 
 class ExprOptimizer {
 private: