Is it possible to perform a read operation from a channel without using a buffer?

In Go, the read operation from a channel (chan) without using a buffer is only possible if the channel is buffered. If the channel is unbuffered (buffer size 0), then the read operation blocks until a value is sent to the channel.

Thus:

• For non-blocking read without a buffer, you need to use non-blocking operations with the channel (for example, via select with default), but this does not guarantee data reception.
• If the channel is unbuffered, reading always blocks until someone sends data.

Example of a buffered channel:

ch := make(chan int, 1) // buffer of 1 element
ch <- 42                // send value
val := <-ch             // read without blocking

If the channel is unbuffered, read and write are synchronized directly between goroutines.