true if the key is a valid HiBON key
// Check is_key_valid import std.algorithm.iteration : each, map; import std.conv : to; import std.range : iota; assert(!is_key_valid("")); string text = " "; // SPACE assert(!is_key_valid(text)); text = [0x80]; // Only simple ASCII assert(!is_key_valid(text)); text = [char(34)]; // Double quote assert(!is_key_valid(text)); text = "'"; // Sigle quote assert(!is_key_valid(text)); text = "`"; // Back quote assert(!is_key_valid(text)); text = "\0"; assert(!is_key_valid(text)); assert(is_key_valid("abc")); assert(is_key_valid(42.to!string)); text = ""; iota(0, ubyte.max).each!((i) => text ~= 'a'); assert(is_key_valid(text)); text ~= 'B'; assert(is_key_valid(text));