add working signup + login

internal/concurrent/value.go

@@ -0,0 +1,30 @@
+package concurrent
+
+import "sync"
+
+// Value is a struct providing concurrent access to another type.
+// Note: T should be a concrete type, not a pointer.
+type Value[T any] struct {
+	val T
+	mu  sync.RWMutex
+}
+
+func NewValue[T any](value T) *Value[T] {
+	return &Value[T]{
+		val: value,
+	}
+}
+
+func (v *Value[T]) Get() T {
+	v.mu.RLock()
+	val := v.val
+	v.mu.RUnlock()
+
+	return val
+}
+
+func (v *Value[T]) Set(new T) {
+	v.mu.Lock()
+	v.val = new
+	v.mu.Unlock()
+}