printf - raw string literal with format macro of fixed width integer types

Question

How do I use raw string literal R with format macro of fixed width integer types?

For example

std::int64_t num = INT64_MAX;
std::printf(R"("name":"%s", "number":"%")" PRId64, "david", num); // wrong syntax

The output should be

"name":"david", "number":"9223372036854775807"

Use of escape sequences instead of R is not permitted

Answer 1

Firstly, you should check your current format string with puts().

#include <cstdio>
#include <cinttypes>

int main(void) {
    std::puts(R"("name":"%s", "number":"%")" PRId64);
    return 0;
}

Result:

"name":"%s", "number":"%"ld

Now you see the errors:

• You have an extra " between % and ld.
• " is missing after ld.

Based on this, fix the format string:

#include <cstdio>
#include <cinttypes>

int main(void) {
    std::int64_t num = INT64_MAX;
    std::printf(R"("name":"%s", "number":"%)" PRId64 R"(")", "david", num);
    return 0;
}

Result:

"name":"david", "number":"9223372036854775807"