SKIP: FAILED

#include <metal_stdlib>
using namespace metal;

threadgroup float2x2 m00;
threadgroup float2x2 m01;
threadgroup float2x2 m02;
threadgroup float2x2 m03;
threadgroup float2x2 m04;
threadgroup float2x2 m05;
threadgroup float2x2 m06;
threadgroup float2x2 m07;
threadgroup float2x2 m08;
threadgroup float2x2 m09;
threadgroup float2x2 m10;
threadgroup float2x2 m11;
threadgroup float2x2 m12;
threadgroup float2x2 m13;
threadgroup float2x2 m14;
threadgroup float2x2 m15;
threadgroup float2x2 m16;
threadgroup float2x2 m17;
threadgroup float2x2 m18;
threadgroup float2x2 m19;
threadgroup float2x2 m20;
threadgroup float2x2 m21;
threadgroup float2x2 m22;
threadgroup float2x2 m23;
threadgroup float2x2 m24;
threadgroup float2x2 m25;
threadgroup float2x2 m26;
threadgroup float2x2 m27;
threadgroup float2x2 m28;
threadgroup float2x2 m29;
threadgroup float2x2 m30;
threadgroup float2x2 m31;
threadgroup float2x2 m32;
threadgroup float2x2 m33;
threadgroup float2x2 m34;
threadgroup float2x2 m35;
threadgroup float2x2 m36;
threadgroup float2x2 m37;
threadgroup float2x2 m38;
threadgroup float2x2 m39;
threadgroup float2x2 m40;
threadgroup float2x2 m41;
threadgroup float2x2 m42;
threadgroup float2x2 m43;
threadgroup float2x2 m44;
threadgroup float2x2 m45;
threadgroup float2x2 m46;
threadgroup float2x2 m47;
threadgroup float2x2 m48;
threadgroup float2x2 m49;
threadgroup float2x2 m50;
threadgroup float2x2 m51;
threadgroup float2x2 m52;
threadgroup float2x2 m53;
threadgroup float2x2 m54;
threadgroup float2x2 m55;
threadgroup float2x2 m56;
threadgroup float2x2 m57;
threadgroup float2x2 m58;
threadgroup float2x2 m59;
threadgroup float2x2 m60;
threadgroup float2x2 m61;
threadgroup float2x2 m62;
threadgroup float2x2 m63;
threadgroup float2x2 m64;
threadgroup float2x2 m65;
threadgroup float2x2 m66;
threadgroup float2x2 m67;
threadgroup float2x2 m68;
threadgroup float2x2 m69;
threadgroup float2x2 m70;
threadgroup float2x2 m71;
threadgroup float2x2 m72;
threadgroup float2x2 m73;
threadgroup float2x2 m74;
threadgroup float2x2 m75;
threadgroup float2x2 m76;
threadgroup float2x2 m77;
threadgroup float2x2 m78;
threadgroup float2x2 m79;
threadgroup float2x2 m80;
threadgroup float2x2 m81;
threadgroup float2x2 m82;
threadgroup float2x2 m83;
threadgroup float2x2 m84;
threadgroup float2x2 m85;
threadgroup float2x2 m86;
threadgroup float2x2 m87;
threadgroup float2x2 m88;
threadgroup float2x2 m89;
threadgroup float2x2 m90;
threadgroup float2x2 m91;
threadgroup float2x2 m92;
threadgroup float2x2 m93;
threadgroup float2x2 m94;
threadgroup float2x2 m95;
threadgroup float2x2 m96;
threadgroup float2x2 m97;
threadgroup float2x2 m98;
threadgroup float2x2 m99;
kernel void tint_symbol(uint idx [[thread_index_in_threadgroup]]) {
  if ((idx == 0u)) {
    m00 = float2x2(float2(0.0f), float2(0.0f));
    m01 = float2x2(float2(0.0f), float2(0.0f));
    m02 = float2x2(float2(0.0f), float2(0.0f));
    m03 = float2x2(float2(0.0f), float2(0.0f));
    m04 = float2x2(float2(0.0f), float2(0.0f));
    m05 = float2x2(float2(0.0f), float2(0.0f));
    m06 = float2x2(float2(0.0f), float2(0.0f));
    m07 = float2x2(float2(0.0f), float2(0.0f));
    m08 = float2x2(float2(0.0f), float2(0.0f));
    m09 = float2x2(float2(0.0f), float2(0.0f));
    m10 = float2x2(float2(0.0f), float2(0.0f));
    m11 = float2x2(float2(0.0f), float2(0.0f));
    m12 = float2x2(float2(0.0f), float2(0.0f));
    m13 = float2x2(float2(0.0f), float2(0.0f));
    m14 = float2x2(float2(0.0f), float2(0.0f));
    m15 = float2x2(float2(0.0f), float2(0.0f));
    m16 = float2x2(float2(0.0f), float2(0.0f));
    m17 = float2x2(float2(0.0f), float2(0.0f));
    m18 = float2x2(float2(0.0f), float2(0.0f));
    m19 = float2x2(float2(0.0f), float2(0.0f));
    m20 = float2x2(float2(0.0f), float2(0.0f));
    m21 = float2x2(float2(0.0f), float2(0.0f));
    m22 = float2x2(float2(0.0f), float2(0.0f));
    m23 = float2x2(float2(0.0f), float2(0.0f));
    m24 = float2x2(float2(0.0f), float2(0.0f));
    m25 = float2x2(float2(0.0f), float2(0.0f));
    m26 = float2x2(float2(0.0f), float2(0.0f));
    m27 = float2x2(float2(0.0f), float2(0.0f));
    m28 = float2x2(float2(0.0f), float2(0.0f));
    m29 = float2x2(float2(0.0f), float2(0.0f));
    m30 = float2x2(float2(0.0f), float2(0.0f));
    m31 = float2x2(float2(0.0f), float2(0.0f));
    m32 = float2x2(float2(0.0f), float2(0.0f));
    m33 = float2x2(float2(0.0f), float2(0.0f));
    m34 = float2x2(float2(0.0f), float2(0.0f));
    m35 = float2x2(float2(0.0f), float2(0.0f));
    m36 = float2x2(float2(0.0f), float2(0.0f));
    m37 = float2x2(float2(0.0f), float2(0.0f));
    m38 = float2x2(float2(0.0f), float2(0.0f));
    m39 = float2x2(float2(0.0f), float2(0.0f));
    m40 = float2x2(float2(0.0f), float2(0.0f));
    m41 = float2x2(float2(0.0f), float2(0.0f));
    m42 = float2x2(float2(0.0f), float2(0.0f));
    m43 = float2x2(float2(0.0f), float2(0.0f));
    m44 = float2x2(float2(0.0f), float2(0.0f));
    m45 = float2x2(float2(0.0f), float2(0.0f));
    m46 = float2x2(float2(0.0f), float2(0.0f));
    m47 = float2x2(float2(0.0f), float2(0.0f));
    m48 = float2x2(float2(0.0f), float2(0.0f));
    m49 = float2x2(float2(0.0f), float2(0.0f));
    m50 = float2x2(float2(0.0f), float2(0.0f));
    m51 = float2x2(float2(0.0f), float2(0.0f));
    m52 = float2x2(float2(0.0f), float2(0.0f));
    m53 = float2x2(float2(0.0f), float2(0.0f));
    m54 = float2x2(float2(0.0f), float2(0.0f));
    m55 = float2x2(float2(0.0f), float2(0.0f));
    m56 = float2x2(float2(0.0f), float2(0.0f));
    m57 = float2x2(float2(0.0f), float2(0.0f));
    m58 = float2x2(float2(0.0f), float2(0.0f));
    m59 = float2x2(float2(0.0f), float2(0.0f));
    m60 = float2x2(float2(0.0f), float2(0.0f));
    m61 = float2x2(float2(0.0f), float2(0.0f));
    m62 = float2x2(float2(0.0f), float2(0.0f));
    m63 = float2x2(float2(0.0f), float2(0.0f));
    m64 = float2x2(float2(0.0f), float2(0.0f));
    m65 = float2x2(float2(0.0f), float2(0.0f));
    m66 = float2x2(float2(0.0f), float2(0.0f));
    m67 = float2x2(float2(0.0f), float2(0.0f));
    m68 = float2x2(float2(0.0f), float2(0.0f));
    m69 = float2x2(float2(0.0f), float2(0.0f));
    m70 = float2x2(float2(0.0f), float2(0.0f));
    m71 = float2x2(float2(0.0f), float2(0.0f));
    m72 = float2x2(float2(0.0f), float2(0.0f));
    m73 = float2x2(float2(0.0f), float2(0.0f));
    m74 = float2x2(float2(0.0f), float2(0.0f));
    m75 = float2x2(float2(0.0f), float2(0.0f));
    m76 = float2x2(float2(0.0f), float2(0.0f));
    m77 = float2x2(float2(0.0f), float2(0.0f));
    m78 = float2x2(float2(0.0f), float2(0.0f));
    m79 = float2x2(float2(0.0f), float2(0.0f));
    m80 = float2x2(float2(0.0f), float2(0.0f));
    m81 = float2x2(float2(0.0f), float2(0.0f));
    m82 = float2x2(float2(0.0f), float2(0.0f));
    m83 = float2x2(float2(0.0f), float2(0.0f));
    m84 = float2x2(float2(0.0f), float2(0.0f));
    m85 = float2x2(float2(0.0f), float2(0.0f));
    m86 = float2x2(float2(0.0f), float2(0.0f));
    m87 = float2x2(float2(0.0f), float2(0.0f));
    m88 = float2x2(float2(0.0f), float2(0.0f));
    m89 = float2x2(float2(0.0f), float2(0.0f));
    m90 = float2x2(float2(0.0f), float2(0.0f));
    m91 = float2x2(float2(0.0f), float2(0.0f));
    m92 = float2x2(float2(0.0f), float2(0.0f));
    m93 = float2x2(float2(0.0f), float2(0.0f));
    m94 = float2x2(float2(0.0f), float2(0.0f));
    m95 = float2x2(float2(0.0f), float2(0.0f));
    m96 = float2x2(float2(0.0f), float2(0.0f));
    m97 = float2x2(float2(0.0f), float2(0.0f));
    m98 = float2x2(float2(0.0f), float2(0.0f));
    m99 = float2x2(float2(0.0f), float2(0.0f));
  }
  threadgroup_barrier(mem_flags::mem_threadgroup);
  m00[0][0] = 1.0f;
  m01[0][0] = 1.0f;
  m02[0][0] = 1.0f;
  m03[0][0] = 1.0f;
  m04[0][0] = 1.0f;
  m05[0][0] = 1.0f;
  m06[0][0] = 1.0f;
  m07[0][0] = 1.0f;
  m08[0][0] = 1.0f;
  m09[0][0] = 1.0f;
  m10[0][0] = 1.0f;
  m11[0][0] = 1.0f;
  m12[0][0] = 1.0f;
  m13[0][0] = 1.0f;
  m14[0][0] = 1.0f;
  m15[0][0] = 1.0f;
  m16[0][0] = 1.0f;
  m17[0][0] = 1.0f;
  m18[0][0] = 1.0f;
  m19[0][0] = 1.0f;
  m20[0][0] = 1.0f;
  m21[0][0] = 1.0f;
  m22[0][0] = 1.0f;
  m23[0][0] = 1.0f;
  m24[0][0] = 1.0f;
  m25[0][0] = 1.0f;
  m26[0][0] = 1.0f;
  m27[0][0] = 1.0f;
  m28[0][0] = 1.0f;
  m29[0][0] = 1.0f;
  m30[0][0] = 1.0f;
  m31[0][0] = 1.0f;
  m32[0][0] = 1.0f;
  m33[0][0] = 1.0f;
  m34[0][0] = 1.0f;
  m35[0][0] = 1.0f;
  m36[0][0] = 1.0f;
  m37[0][0] = 1.0f;
  m38[0][0] = 1.0f;
  m39[0][0] = 1.0f;
  m40[0][0] = 1.0f;
  m41[0][0] = 1.0f;
  m42[0][0] = 1.0f;
  m43[0][0] = 1.0f;
  m44[0][0] = 1.0f;
  m45[0][0] = 1.0f;
  m46[0][0] = 1.0f;
  m47[0][0] = 1.0f;
  m48[0][0] = 1.0f;
  m49[0][0] = 1.0f;
  m50[0][0] = 1.0f;
  m51[0][0] = 1.0f;
  m52[0][0] = 1.0f;
  m53[0][0] = 1.0f;
  m54[0][0] = 1.0f;
  m55[0][0] = 1.0f;
  m56[0][0] = 1.0f;
  m57[0][0] = 1.0f;
  m58[0][0] = 1.0f;
  m59[0][0] = 1.0f;
  m60[0][0] = 1.0f;
  m61[0][0] = 1.0f;
  m62[0][0] = 1.0f;
  m63[0][0] = 1.0f;
  m64[0][0] = 1.0f;
  m65[0][0] = 1.0f;
  m66[0][0] = 1.0f;
  m67[0][0] = 1.0f;
  m68[0][0] = 1.0f;
  m69[0][0] = 1.0f;
  m70[0][0] = 1.0f;
  m71[0][0] = 1.0f;
  m72[0][0] = 1.0f;
  m73[0][0] = 1.0f;
  m74[0][0] = 1.0f;
  m75[0][0] = 1.0f;
  m76[0][0] = 1.0f;
  m77[0][0] = 1.0f;
  m78[0][0] = 1.0f;
  m79[0][0] = 1.0f;
  m80[0][0] = 1.0f;
  m81[0][0] = 1.0f;
  m82[0][0] = 1.0f;
  m83[0][0] = 1.0f;
  m84[0][0] = 1.0f;
  m85[0][0] = 1.0f;
  m86[0][0] = 1.0f;
  m87[0][0] = 1.0f;
  m88[0][0] = 1.0f;
  m89[0][0] = 1.0f;
  m90[0][0] = 1.0f;
  m91[0][0] = 1.0f;
  m92[0][0] = 1.0f;
  m93[0][0] = 1.0f;
  m94[0][0] = 1.0f;
  m95[0][0] = 1.0f;
  m96[0][0] = 1.0f;
  m97[0][0] = 1.0f;
  m98[0][0] = 1.0f;
  m99[0][0] = 1.0f;
}
program_source:4:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m00;
                     ^
program_source:5:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m01;
                     ^
program_source:6:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m02;
                     ^
program_source:7:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m03;
                     ^
program_source:8:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m04;
                     ^
program_source:9:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m05;
                     ^
program_source:10:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m06;
                     ^
program_source:11:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m07;
                     ^
program_source:12:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m08;
                     ^
program_source:13:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m09;
                     ^
program_source:14:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m10;
                     ^
program_source:15:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m11;
                     ^
program_source:16:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m12;
                     ^
program_source:17:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m13;
                     ^
program_source:18:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m14;
                     ^
program_source:19:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m15;
                     ^
program_source:20:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m16;
                     ^
program_source:21:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m17;
                     ^
program_source:22:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m18;
                     ^
program_source:23:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m19;
                     ^
program_source:24:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m20;
                     ^
program_source:25:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m21;
                     ^
program_source:26:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m22;
                     ^
program_source:27:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m23;
                     ^
program_source:28:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m24;
                     ^
program_source:29:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m25;
                     ^
program_source:30:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m26;
                     ^
program_source:31:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m27;
                     ^
program_source:32:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m28;
                     ^
program_source:33:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m29;
                     ^
program_source:34:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m30;
                     ^
program_source:35:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m31;
                     ^
program_source:36:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m32;
                     ^
program_source:37:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m33;
                     ^
program_source:38:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m34;
                     ^
program_source:39:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m35;
                     ^
program_source:40:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m36;
                     ^
program_source:41:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m37;
                     ^
program_source:42:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m38;
                     ^
program_source:43:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m39;
                     ^
program_source:44:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m40;
                     ^
program_source:45:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m41;
                     ^
program_source:46:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m42;
                     ^
program_source:47:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m43;
                     ^
program_source:48:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m44;
                     ^
program_source:49:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m45;
                     ^
program_source:50:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m46;
                     ^
program_source:51:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m47;
                     ^
program_source:52:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m48;
                     ^
program_source:53:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m49;
                     ^
program_source:54:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m50;
                     ^
program_source:55:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m51;
                     ^
program_source:56:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m52;
                     ^
program_source:57:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m53;
                     ^
program_source:58:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m54;
                     ^
program_source:59:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m55;
                     ^
program_source:60:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m56;
                     ^
program_source:61:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m57;
                     ^
program_source:62:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m58;
                     ^
program_source:63:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m59;
                     ^
program_source:64:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m60;
                     ^
program_source:65:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m61;
                     ^
program_source:66:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m62;
                     ^
program_source:67:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m63;
                     ^
program_source:68:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m64;
                     ^
program_source:69:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m65;
                     ^
program_source:70:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m66;
                     ^
program_source:71:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m67;
                     ^
program_source:72:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m68;
                     ^
program_source:73:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m69;
                     ^
program_source:74:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m70;
                     ^
program_source:75:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m71;
                     ^
program_source:76:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m72;
                     ^
program_source:77:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m73;
                     ^
program_source:78:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m74;
                     ^
program_source:79:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m75;
                     ^
program_source:80:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m76;
                     ^
program_source:81:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m77;
                     ^
program_source:82:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m78;
                     ^
program_source:83:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m79;
                     ^
program_source:84:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m80;
                     ^
program_source:85:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m81;
                     ^
program_source:86:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m82;
                     ^
program_source:87:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m83;
                     ^
program_source:88:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m84;
                     ^
program_source:89:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m85;
                     ^
program_source:90:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m86;
                     ^
program_source:91:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m87;
                     ^
program_source:92:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m88;
                     ^
program_source:93:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m89;
                     ^
program_source:94:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m90;
                     ^
program_source:95:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m91;
                     ^
program_source:96:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m92;
                     ^
program_source:97:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m93;
                     ^
program_source:98:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m94;
                     ^
program_source:99:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m95;
                     ^
program_source:100:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m96;
                     ^
program_source:101:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m97;
                     ^
program_source:102:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m98;
                     ^
program_source:103:22: error: program scope variable must reside in constant address space
threadgroup float2x2 m99;
                     ^
program_source:105:12: warning: equality comparison with extraneous parentheses [-Wparentheses-equality]
  if ((idx == 0u)) {
       ~~~~^~~~~
program_source:105:12: note: remove extraneous parentheses around the comparison to silence this warning
  if ((idx == 0u)) {
      ~    ^    ~
program_source:105:12: note: use '=' to turn this equality comparison into an assignment
  if ((idx == 0u)) {
           ^~
           =