gcc 7.0(HEAD) -std=c++1z -03

input.cpp

#include <cstdio>
#include <string>

int main() {
  using namespace std::literals::string_view_literals;
  for (char c: "Hello"sv) {
    std::printf("(%d)", c);
  }
}

outout.s

.LC0:
        .string "Hello"
.LC1:
        .string "(%d)"
main:
        pushq   %rbp
        pushq   %rbx
        movl    $.LC0+5, %ebp
        movl    $.LC0, %ebx
        subq    $8, %rsp
.L2:
        movsbl  (%rbx), %esi
        xorl    %eax, %eax
        movl    $.LC1, %edi
        addq    $1, %rbx
        call    printf
        cmpq    %rbx, %rbp
        jne     .L2
        addq    $8, %rsp
        xorl    %eax, %eax
        popq    %rbx
        popq    %rbp
        ret

http://d.hatena.ne.jp/yohhoy/20161204/p1 (ja)