append to a slice without needing the "assign to same variable" boilerplate.

errors if a field is unset.

helper for wrapping an error with error prefix.

returns first error, or nil if no errors Deprecated: use `FirstNonEmpty()`.

returns the first non-empty value.

ignores error in situations where context was canceled and thus errors are to be expected and thus are non-interesting.

for a function that returns two values, you can get the value with `Must(fn())` to convert it to the value, panicking if producing the value caused an error.

returns a pointer to the given value.

empty struct with a semantic name, meaning no information is conveyed.