[libFuzzer] replace std::random_shuffle with std::shuffle as std::random_shuffle is being deprecated in C++17. Also simplify fuzzer::Random. NFC

llvm-svn: 294366

1 files changed, 4 insertions, 6 deletions

diff --git a/llvm/lib/Fuzzer/FuzzerRandom.h b/llvm/lib/Fuzzer/FuzzerRandom.h
index b1be0bb935f..8a1aa3ef5fd 100644
--- a/llvm/lib/Fuzzer/FuzzerRandom.h
+++ b/llvm/lib/Fuzzer/FuzzerRandom.h
@@ -15,10 +15,11 @@
 #include <random>
 
 namespace fuzzer {
-class Random {
+class Random : public std::mt19937 {
  public:
-  Random(unsigned int seed) : R(seed) {}
-  size_t Rand() { return R(); }
+  Random(unsigned int seed) : std::mt19937(seed) {}
+  result_type operator()() { return this->std::mt19937::operator()(); }
+  size_t Rand() { return this->operator()(); }
   size_t RandBool() { return Rand() % 2; }
   size_t operator()(size_t n) { return n ? Rand() % n : 0; }
   intptr_t operator()(intptr_t From, intptr_t To) {
@@ -26,9 +27,6 @@ class Random {
     intptr_t RangeSize = To - From + 1;
     return operator()(RangeSize) + From;
   }
-  std::mt19937 &Get_mt19937() { return R; }
- private:
-  std::mt19937 R;
 };
 
 }  // namespace fuzzer