Ensure single-argument constructors are explicit

lib/check.h

@@ -38,7 +38,7 @@
 class Check {
 public:
     /** This constructor is used when registering the CheckClass */
-    Check(const std::string &aname);
+    explicit Check(const std::string &aname);
 
     /** This constructor is used when running checks. */
     Check(const std::string &aname, const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)

lib/checkbufferoverrun.cpp

@@ -191,7 +191,7 @@ public:
     /**
      * @param str Token::str() is compared against this.
      */
-    TokenStrEquals(const std::string &str)
+    explicit TokenStrEquals(const std::string &str)
         : value(str) {
     }
 

lib/checknullpointer.cpp

@@ -940,7 +940,7 @@ void CheckNullPointer::nullConstantDereference()
 class Nullpointer : public ExecutionPath {
 public:
     /** Startup constructor */
-    Nullpointer(Check *c) : ExecutionPath(c, 0), null(false) {
+    explicit Nullpointer(Check *c) : ExecutionPath(c, 0), null(false) {
     }
 
 private:

lib/checkuninitvar.cpp

@@ -41,7 +41,7 @@ namespace {
 class UninitVar : public ExecutionPath {
 public:
     /** Startup constructor */
-    UninitVar(Check *c)
+    explicit UninitVar(Check *c)
         : ExecutionPath(c, 0), pointer(false), array(false), alloc(false), strncpy_(false), memset_nonzero(false) {
     }
 

lib/preprocessor.cpp

@@ -2167,7 +2167,7 @@ public:
      * @param macro The code after define, until end of line,
      * e.g. "A(x) foo(x);"
      */
-    PreprocessorMacro(const std::string &macro)
+    explicit PreprocessorMacro(const std::string &macro)
         : _macro(macro), _prefix("__cppcheck__") {
         tokenizer.setSettings(&settings);
 

lib/token.h

@@ -43,7 +43,7 @@ private:
     Token();
 
 public:
-    Token(Token **tokensBack);
+    explicit Token(Token **tokensBack);
     ~Token();
 
     void str(const std::string &s);