Rework fixed strings handling

apps/openmw_test_suite/esm/test_fixed_string.cpp

@@ -97,7 +97,6 @@ TEST(EsmFixedString, struct_size)
     ASSERT_EQ(4, sizeof(ESM::NAME));
     ASSERT_EQ(32, sizeof(ESM::NAME32));
     ASSERT_EQ(64, sizeof(ESM::NAME64));
-    ASSERT_EQ(256, sizeof(ESM::NAME256));
 }
 
 TEST(EsmFixedString, is_pod)
@@ -105,5 +104,4 @@ TEST(EsmFixedString, is_pod)
      ASSERT_TRUE(std::is_pod<ESM::NAME>::value);
      ASSERT_TRUE(std::is_pod<ESM::NAME32>::value);
      ASSERT_TRUE(std::is_pod<ESM::NAME64>::value);
-     ASSERT_TRUE(std::is_pod<ESM::NAME256>::value);
 }

components/esm/esmcommon.hpp

@@ -6,7 +6,6 @@
 #include <vector>
 
 #include <stdint.h>
-#include <string.h>
 
 namespace ESM
 {
@@ -57,11 +56,16 @@ public:
     }
     bool operator!=(const std::string& str) const { return !( (*this) == str ); }
 
-    size_t data_size() const { return size; }
+    static size_t data_size() { return size; }
     size_t length() const { return strnlen(self()->ro_data(), size); }
     std::string toString() const { return std::string(self()->ro_data(), this->length()); }
 
-    void assign(const std::string& value) { std::strncpy(self()->rw_data(), value.c_str(), size); }
+    void assign(const std::string& value)
+    {
+        std::strncpy(self()->rw_data(), value.c_str(), size-1);
+        self()->rw_data()[size-1] = '\0';
+    }
+
     void clear() { this->assign(""); }
 private:
     DERIVED<size> const* self() const
@@ -103,6 +107,20 @@ struct FIXED_STRING<4> : public FIXED_STRING_BASE<FIXED_STRING, 4>
     bool operator==(uint32_t v) const { return v == intval; }
     bool operator!=(uint32_t v) const { return v != intval; }
 
+    void assign(const std::string& value)
+    {
+        intval = 0;
+        size_t length = value.size();
+        if (length == 0) return;
+        data[0] = value[0];
+        if (length == 1) return;
+        data[1] = value[1];
+        if (length == 2) return;
+        data[2] = value[2];
+        if (length == 3) return;
+        data[3] = value[3];
+    }
+
     char const* ro_data() const { return data; }
     char*       rw_data() { return data; }
 };
@@ -110,7 +128,6 @@ struct FIXED_STRING<4> : public FIXED_STRING_BASE<FIXED_STRING, 4>
 typedef FIXED_STRING<4> NAME;
 typedef FIXED_STRING<32> NAME32;
 typedef FIXED_STRING<64> NAME64;
-typedef FIXED_STRING<256> NAME256;
 
 /* This struct defines a file 'context' which can be saved and later
    restored by an ESMReader instance. It will save the position within