Subzero: Improve class definition hygiene.

src/IceRNG.h

 //===- subzero/src/IceRNG.h - Random number generator -----------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares a random number generator.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICERNG_H
 #define SUBZERO_SRC_ICERNG_H
 
 #include <cstdint>
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Compiler.h"
 
 namespace Ice {
 
 class RandomNumberGenerator {
+  RandomNumberGenerator() = delete;
   RandomNumberGenerator(const RandomNumberGenerator &) = delete;
   RandomNumberGenerator &operator=(const RandomNumberGenerator &) = delete;
 
 public:
-  RandomNumberGenerator(llvm::StringRef Salt);
+  explicit RandomNumberGenerator(llvm::StringRef Salt);
   uint64_t next(uint64_t Max);
 
 private:
   uint64_t State;
 };
 
 // This class adds additional random number generator utilities. The
 // reason for the wrapper class is that we want to keep the
 // RandomNumberGenerator interface identical to LLVM's.
 class RandomNumberGeneratorWrapper {
+  RandomNumberGeneratorWrapper() = delete;
   RandomNumberGeneratorWrapper(const RandomNumberGeneratorWrapper &) = delete;
   RandomNumberGeneratorWrapper &
   operator=(const RandomNumberGeneratorWrapper &) = delete;
 
 public:
   uint64_t operator()(uint64_t Max) { return RNG.next(Max); }
   bool getTrueWithProbability(float Probability);
-  RandomNumberGeneratorWrapper(RandomNumberGenerator &RNG) : RNG(RNG) {}
+  explicit RandomNumberGeneratorWrapper(RandomNumberGenerator &RNG)
+      : RNG(RNG) {}
 
 private:
   RandomNumberGenerator &RNG;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICERNG_H