[Issue 17764] [scope][DIP1000] Escape checker defeated by composition transformations

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=17764

Walter Bright <bugzilla at digitalmars.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |INVALID

--- Comment #3 from Walter Bright <bugzilla at digitalmars.com> ---
The following remain:

---
@safe:
struct Context0x0 { char[]       str; }

struct Parent0x1 { Context0x0      c; }
struct Parent0x2 { Context0x0[1] csa; }
struct Parent0x3 { Context0x0[]  csl; }
struct Parent0x4 { Context0x0*    cp; }

struct Parent0x5 { Parent0x1      p1; }
struct Parent0x6 { Parent0x5      p5; }
struct Parent0x7 { Parent0x6      p6; }

struct Parent0x8 { Parent0x2[1]*  p2; }
struct Parent0x9 { Parent0x8[1]   p8; }
struct Parent0xA { Parent0x9[1]   p9; }

struct Parent0xB { Parent0x4*     p4; }
struct Parent0xC { Parent0xB*     pb; }
struct Parent0xD { Parent0xC*     pc; }

char[] global;

void use0x2(scope char[]* arr)
{
    global = *arr; // NG - accepts invalid
}

void use0x9(scope ref Parent0x4 p)
{
    global = p.cp.str; // NG - accepts invalid
}

void use0xB(scope ref Parent0xA p)
{
    global = (*p.p9[0].p8[0].p2)[0].csa[0].str; // NG - accepts invalid
}

void use0xC(scope ref Parent0xD p)
{
    global = p.pc.pb.p4.cp.str; // NG - accepts invalid
}
---

All of them are instances of transitive scope, but scope is not transitive. Not
compiler bugs.

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