Joining an iterable of strings into a single string. Python does: seperator.join(iterable) "".join(["foo", "bar", "hello"]) # => "foobarhello" ", ".join(

Joining an iterable of strings into a single string. Python does: seperator.join(iterable) "".join(["foo", "bar", "hello"]) # => "foobarhello" ", ".join(["Hacker News", "Twitter"]) # => "Hacker News, Twitter Many people have complained about this strange syntax: https://mail.python.org/archives/list/python-ideas@python.org/thread/LOJEKT2BIGGYXTR7GUBL3BMX2GZUAEEK/#QWJNKMI4KAZUVPDJTHYOHC65GQ7ILJSV https://mail.python.org/archives/list/python-ideas@python.or... https://mail.python.org/archives/list/python-ideas@python.org/thread/JNBEZSOWDWPQGQ6A2EXM32FGKYXVRHZM/#V7DEV5W6SXJWRD65UKNMOWWQOUIGMLYH https://mail.python.org/archives/list/python-ideas@python.or... https://mail.python.org/archives/list/python-ideas@python.org/thread/JNBEZSOWDWPQGQ6A2EXM32FGKYXVRHZM/#DXIZW67RUGRUYJERYFTRRSK3I4T4DNYU https://mail.python.org/archives/list/python-ideas@python.or... https://mail.python.org/archives/list/python-ideas@python.org/thread/LOJEKT2BIGGYXTR7GUBL3BMX2GZUAEEK/#YOGIBUP5OJEGZJO2YKNDH4NHPAEIFBS4 https://mail.python.org/archives/list/python-ideas@python.or... `["a", "b", "c"].join(iterable)` was rejected because it forces every iterable to implement iterable functions. Additionally some iterables, like generators, are mutated when you iterate over them: ", ".join(streaming_api.fetch_names()) UFCS let's you write join as a free function and still use "".join(iterable) NaN guarding: import std.traits; auto unwrap(T)(T input) if (isFloatingPoint!T) { // Asserts cost nothing when turned off with -check=assert=off // The compiler can fully inline this function, so it isn't expensive assert(input !== input.nan); return input; } Use like this: if (objSize.unwrap < cellSize) { // Allocate a new cell for the object } else { // Insert into current cell } The parentheses are omitted because Dlang has https://dlang.org/spec/function.html#optional-parenthesis https://dlang.org/spec/function.html#optional-parenthesis. The above compiles into this: if (objSize.unwrap() < cellSize) { // Allocate a new cell for the object } else { // Insert into current cell }