Re: build error --std=c++17 vs --std=c++23 -Wrestrict "may overlap up to 9223372036854775813 bytes at offset -3"

["Saifi Khan" <saifi.khan@xxxxxxxxx>]

>  -------Original Message-------
>  From: Jonathan Wakely via Gcc-help <gcc-help@xxxxxxxxxxx>
>  To: Saifi Khan <saifi.khan@xxxxxxxxx>
>  Cc: gcc-help@xxxxxxxxxxx <gcc-help@xxxxxxxxxxx>
>  Subject: Re: build error --std=c++17 vs --std=c++23 -Wrestrict "may overlap up to 9223372036854775813 bytes at offset -3"
>  Sent: 2023-02-23 16:33
>  
>  On Thu, 23 Feb 2023 at 14:10, Saifi Khan wrote:
>  >
>  > Hi:
>  >
>  > Tried Jonny Grant's example
>  > g++ -O3 --std=c++23 -Wall -c repro_jg01.cc
>  
>  Context please - which example is that? 

#include <string>

typedef struct a_bc
{
    std::string a;
    std::string b;
} a_t;

void f()
{
    a_t c;

    c.a = " sdfsdf fsdfsdf fdfsfdsdf ";   // seems to need this long string to reproduce, down to 8 bytes it didn't
    c.b = "E";
}

Here is a verbatim copy of the the sample code, in which the OP encountered build error(s) with gcc 12.2.x

warm regards
Saifi.