//ww:run-exit 46
// Migrated from 777_fmt_handle_run row fprintf_stream.
package main;
import os;
import fmt;
import io;
import memio;
export fn main() i32 = {
    let buf: [16]u8;
    let st: memio.stream = memio.fixed(buf[0:16]);
    let s: io.stream = &st.vt;
    let wr = fmt.fprintf(s, "v={}\n", 42i64);
    let nw: size = 0;
    match (wr) {
    case let n: size => { nw = n; };
    case io.error => { return 91; };
    };
    if (nw != 5: size) { return 94; };
    let view: str = memio.string(&st);
    if (view.len != 5) { return 93; };
    if (view[0] != 118u8 || view[1] != 61u8 || view[2] != 52u8 || view[3] != 50u8 || view[4] != 10u8) { return 95; };
    return 46;
};