fix som cppcheck issues

EasyRandom.cc

@@ -38,15 +38,14 @@ class EasyRandom::GlobalRandom final
 
 private:
   std::mt19937 m_gen{};
-  static const int nchars = 64;
+  static constexpr int nchars = 64;
   static char getChar(int i)
   {
-    const char acceptable_filename_chars[] = "abcdefghijklmnopqrstuvwxyz"
-                                             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-                                             "0123456789"
-                                             "_-";
-    static_assert(nchars + 1 == sizeof(acceptable_filename_chars),
-                  "mismatch in size");
+    const char acceptable_filename_chars[nchars + 1] =
+      "abcdefghijklmnopqrstuvwxyz"
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+      "0123456789"
+      "_-";
     return acceptable_filename_chars[i];
   }
   std::uniform_int_distribution<int> m_dist{ 0, nchars - 1 };
@@ -69,8 +68,7 @@ std::string
 EasyRandom::makeRandomFileString(std::size_t N)
 {
   std::string ret(N, '\0');
-  for (auto& c : ret) {
-    c = m_rand.randomFileChar();
-  }
+  std::generate(
+    begin(ret), end(ret), [this]() { return m_rand.randomFileChar(); });
   return ret;
 }

Fileinfo.cc

@@ -155,12 +155,12 @@ Fileinfo::getduptypestring(const Fileinfo& A)
 
 // constructor
 Fileinfo::Fileinfostat::Fileinfostat()
+  : stat_size{ 99999 }
+  , stat_ino{ 99999 }
+  , stat_dev{ 99999 }
+  , is_file{ false }
+  , is_directory{ false }
 {
-  stat_size = 99999;
-  stat_ino = 99999;
-  stat_dev = 99999;
-  is_file = false;
-  is_directory = false;
 }
 
 int

Fileinfo.hh

@@ -68,7 +68,6 @@ public:
   void setduptype(enum duptype duptype_) { m_duptype = duptype_; }
 
   std::int64_t getidentity() const { return m_identity; }
-  static std::int64_t identity(const Fileinfo& A) { return A.getidentity(); }
   void setidentity(std::int64_t id) { m_identity = id; }
 
   /**
@@ -109,9 +108,6 @@ public:
   /// returns the file size in bytes
   filesizetype size() const { return m_info.stat_size; }
 
-  // returns true if A has size zero
-  bool isempty() const { return size() == 0; }
-
   /// filesize comparison
   bool is_smaller_than(Fileinfo::filesizetype minsize) const
   {

UndoableUnlink.cc

@@ -81,6 +81,9 @@ UndoableUnlink::unlink()
   return 0;
 }
 
+// cppcheck thinks this can throw in undo(), but that contains a check for
+// m_state so that can not happen.
+// cppcheck-suppress throwInNoexceptFunction
 UndoableUnlink::~UndoableUnlink()
 {
   if (m_state == state::MOVED_TO_TEMPORARY) {