Copy constructor is enabled only if T is mutable type without eleborate assign.
Copies data into an array of the same length using memcpy C routine. Shrinks the length to 0.
auto buf = scopedBuffer!char; buf.put('c'); buf.put("str"); assert(buf.data == "cstr"); buf.popBackN(2); assert(buf.data == "cs");
immutable
auto buf = scopedBuffer!(immutable char); buf.put('c'); buf.put("str"); assert(buf.data == "cstr"); buf.popBackN(2); assert(buf.data == "cs");