Magic concatenation: the "+" operator is understood by the compiler to be the concatenation operator if either operand is a String. "Magic" in the sense that it

Magic concatenation: the "+" operator is understood by the compiler to be the concatenation operator if either operand is a String. "Magic" in the sense that it's an exceptional affordance made by the language (not the library) for this one data type and operator. Auto-conversion: "2" + 5 = "25". This looks horribly hackish, like some type buggering perl might do, or js. But it comes in handy when you want to build a message string. And yes, as the article tells us, a lot of things are very purposely left out of Go, which has advantages and disadvantages like most trade-offs.