optimize observable::add/add support for many containers

src/observable.h

@@ -16,10 +16,10 @@ public:
 	const std::string &name() const;
 
 	template<class T>
-	void add(T);
+	auto add(T val) -> decltype(val + val, void());
 
 	template<class T>
-	void add(const std::vector<T> &);
+	auto add(const T& val) -> decltype(val[0], void());
 
 	template<class T>
 	void add(const std::valarray<T> &);
@@ -34,7 +34,6 @@ public:
 	// switch copy with target rank.
 	// useful for parallel tempering mode
 	void mpi_sendrecv(int target_rank);
-
 private:
 	static const size_t initial_bin_length = 1000;
 
@@ -48,38 +47,13 @@ private:
 };
 
 template<class T>
-void observable::add(T val) {
-	std::vector<T> v = {val};
-	add(v);
+auto observable::add(T val) -> decltype(val + val, void()) {
+	add(std::array<T,1>{val});
 }
 
-template<class T>
-void observable::add(const std::vector<T> &val) {
-	if(vector_length_ != val.size()) {
-		throw std::runtime_error{
-		    fmt::format("observable::add: added vector has unexpected size ({}). Observable was "
-		                "initialized with vector length ({})",
-		                val.size(), vector_length_)};
-	}
-
-	for(size_t j = 0; j < vector_length_; ++j)
-		samples_[j + current_bin_ * vector_length_] += static_cast<double>(val[j]);
-	current_bin_filling_++;
-
-	if(current_bin_filling_ == bin_length_) { // need to start a new bin next time
-		if(bin_length_ > 1) {
-			for(size_t j = 0; j < vector_length_; ++j) {
-				samples_[current_bin_ * vector_length_ + j] /= bin_length_;
-			}
-		}
-		current_bin_++;
-		samples_.resize((current_bin_ + 1) * vector_length_);
-		current_bin_filling_ = 0;
-	}
-}
 
 template<class T>
-void observable::add(const std::valarray<T> &val) {
+auto observable::add(const T &val) -> decltype(val[0], void()) {
 	if(vector_length_ != val.size()) {
 		throw std::runtime_error{
 		    fmt::format("observable::add: added vector has unexpected size ({}). Observable was "