[Teton] Load a font file and write a character to the screen.

lib/glacier/container/hash_map.h

@@ -6,6 +6,7 @@
 #include "glacier/container/linked_list.h"
 #include "glacier/container/pair.h"
 #include "glacier/status/error.h"
+#include "glacier/string/string.h"
 
 namespace glcr {
 
@@ -22,6 +23,18 @@ struct HashFunc<uint64_t> {
   }
 };
 
+template <>
+struct HashFunc<String> {
+  uint64_t operator()(const String& value) {
+    // FIXME: Write a real hash function.
+    uint64_t acc = 0;
+    for (uint64_t i = 0; i < value.length(); i++) {
+      acc += value[i];
+    }
+    return 0xABBAABBAABBAABBA ^ acc;
+  }
+};
+
 template <typename K, typename V, class H = HashFunc<K>>
 class HashMap {
  public:

lib/glacier/string/string.cpp

@@ -28,6 +28,46 @@ String::String(const char* cstr, uint64_t str_len) : length_(str_len) {
 
 String::String(StringView str) : String(str.data(), str.size()) {}
 
+String::String(const String& other) : String(other.cstr_, other.length_) {}
+
+String& String::operator=(const String& other) {
+  if (cstr_) {
+    delete cstr_;
+  }
+  length_ = other.length_;
+  cstr_ = new char[length_ + 1];
+  for (uint64_t i = 0; i < length_; i++) {
+    cstr_[i] = other.cstr_[i];
+  }
+  cstr_[length_] = '\0';
+
+  return *this;
+}
+
+String::String(String&& other) : cstr_(other.cstr_), length_(other.length_) {
+  other.cstr_ = nullptr;
+  other.length_ = 0;
+}
+
+String& String::operator=(String&& other) {
+  if (cstr_) {
+    delete cstr_;
+  }
+  cstr_ = other.cstr_;
+  length_ = other.length_;
+
+  other.cstr_ = nullptr;
+  other.length_ = 0;
+
+  return *this;
+}
+
+String::~String() {
+  if (cstr_) {
+    delete cstr_;
+  }
+}
+
 bool String::operator==(const String& other) {
   if (other.length_ != length_) {
     return false;

lib/glacier/string/string.h

@@ -13,7 +13,12 @@ class String {
   String(const char* cstr, uint64_t str_len);
   String(StringView str);
 
-  String(const String&) = delete;
+  String(const String&);
+  String& operator=(const String&);
+  String(String&&);
+  String& operator=(String&&);
+
+  ~String();
 
   const char* cstr() const { return cstr_; }
   uint64_t length() const { return length_; }