types.h

#pragma once

struct Type0 { int x; };
struct Type1 { int x; };
struct Type2 { int x; };
struct Type3 { int x; };
struct Type4 { int x; };
struct Type5 { int x; };
struct Type6 { int x; };
struct Type7 { int x; };
struct Type8 { int x; };
struct Type9 { int x; };
struct Type10 { int x; };
struct Type11 { int x; };
struct Type12 { int x; };
struct Type13 { int x; };
struct Type14 { int x; };
struct Type15 { int x; };
struct Type16 { int x; };
struct Type17 { int x; };
struct Type18 { int x; };
struct Type19 { int x; };
struct Type20 { int x; };
struct Type21 { int x; };
struct Type22 { int x; };
struct Type23 { int x; };
struct Type24 { int x; };
struct Type25 { int x; };
struct Type26 { int x; };
struct Type27 { int x; };
struct Type28 { int x; };
struct Type29 { int x; };
struct Type30 { int x; };
struct Type31 { int x; };
struct Type32 { int x; };
struct Type33 { int x; };
struct Type34 { int x; };
struct Type35 { int x; };
struct Type36 { int x; };
struct Type37 { int x; };
struct Type38 { int x; };
struct Type39 { int x; };
struct Type40 { int x; };
struct Type41 { int x; };
struct Type42 { int x; };
struct Type43 { int x; };
struct Type44 { int x; };
struct Type45 { int x; };
struct Type46 { int x; };
struct Type47 { int x; };
struct Type48 { int x; };
struct Type49 { int x; };
struct Type50 { int x; };
struct Type51 { int x; };
struct Type52 { int x; };
struct Type53 { int x; };
struct Type54 { int x; };
struct Type55 { int x; };
struct Type56 { int x; };
struct Type57 { int x; };
struct Type58 { int x; };
struct Type59 { int x; };
struct Type60 { int x; };
struct Type61 { int x; };
struct Type62 { int x; };
struct Type63 { int x; };
struct Type64 { int x; };
struct Type65 { int x; };
struct Type66 { int x; };
struct Type67 { int x; };
struct Type68 { int x; };
struct Type69 { int x; };
struct Type70 { int x; };
struct Type71 { int x; };
struct Type72 { int x; };
struct Type73 { int x; };
struct Type74 { int x; };
struct Type75 { int x; };
struct Type76 { int x; };
struct Type77 { int x; };
struct Type78 { int x; };
struct Type79 { int x; };
struct Type80 { int x; };
struct Type81 { int x; };
struct Type82 { int x; };
struct Type83 { int x; };
struct Type84 { int x; };
struct Type85 { int x; };
struct Type86 { int x; };
struct Type87 { int x; };
struct Type88 { int x; };
struct Type89 { int x; };
struct Type90 { int x; };
struct Type91 { int x; };
struct Type92 { int x; };
struct Type93 { int x; };
struct Type94 { int x; };
struct Type95 { int x; };
struct Type96 { int x; };
struct Type97 { int x; };
struct Type98 { int x; };
struct Type99 { int x; };
struct Type100 { int x; };
struct Type101 { int x; };
struct Type102 { int x; };
struct Type103 { int x; };
struct Type104 { int x; };
struct Type105 { int x; };
struct Type106 { int x; };
struct Type107 { int x; };
struct Type108 { int x; };
struct Type109 { int x; };
struct Type110 { int x; };
struct Type111 { int x; };
struct Type112 { int x; };
struct Type113 { int x; };
struct Type114 { int x; };
struct Type115 { int x; };
struct Type116 { int x; };
struct Type117 { int x; };
struct Type118 { int x; };
struct Type119 { int x; };
struct Type120 { int x; };
struct Type121 { int x; };
struct Type122 { int x; };
struct Type123 { int x; };
struct Type124 { int x; };
struct Type125 { int x; };
struct Type126 { int x; };
struct Type127 { int x; };
struct Type128 { int x; };
struct Type129 { int x; };
struct Type130 { int x; };
struct Type131 { int x; };
struct Type132 { int x; };
struct Type133 { int x; };
struct Type134 { int x; };
struct Type135 { int x; };
struct Type136 { int x; };
struct Type137 { int x; };
struct Type138 { int x; };
struct Type139 { int x; };
struct Type140 { int x; };
struct Type141 { int x; };
struct Type142 { int x; };
struct Type143 { int x; };
struct Type144 { int x; };
struct Type145 { int x; };
struct Type146 { int x; };
struct Type147 { int x; };
struct Type148 { int x; };
struct Type149 { int x; };
struct Type150 { int x; };
struct Type151 { int x; };
struct Type152 { int x; };
struct Type153 { int x; };
struct Type154 { int x; };
struct Type155 { int x; };
struct Type156 { int x; };
struct Type157 { int x; };
struct Type158 { int x; };
struct Type159 { int x; };
struct Type160 { int x; };
struct Type161 { int x; };
struct Type162 { int x; };
struct Type163 { int x; };
struct Type164 { int x; };
struct Type165 { int x; };
struct Type166 { int x; };
struct Type167 { int x; };
struct Type168 { int x; };
struct Type169 { int x; };
struct Type170 { int x; };
struct Type171 { int x; };
struct Type172 { int x; };
struct Type173 { int x; };
struct Type174 { int x; };
struct Type175 { int x; };
struct Type176 { int x; };
struct Type177 { int x; };
struct Type178 { int x; };
struct Type179 { int x; };
struct Type180 { int x; };
struct Type181 { int x; };
struct Type182 { int x; };
struct Type183 { int x; };
struct Type184 { int x; };
struct Type185 { int x; };
struct Type186 { int x; };
struct Type187 { int x; };
struct Type188 { int x; };
struct Type189 { int x; };
struct Type190 { int x; };
struct Type191 { int x; };
struct Type192 { int x; };
struct Type193 { int x; };
struct Type194 { int x; };
struct Type195 { int x; };
struct Type196 { int x; };
struct Type197 { int x; };
struct Type198 { int x; };
struct Type199 { int x; };
struct Type200 { int x; };
struct Type201 { int x; };
struct Type202 { int x; };
struct Type203 { int x; };
struct Type204 { int x; };
struct Type205 { int x; };
struct Type206 { int x; };
struct Type207 { int x; };
struct Type208 { int x; };
struct Type209 { int x; };
struct Type210 { int x; };
struct Type211 { int x; };
struct Type212 { int x; };
struct Type213 { int x; };
struct Type214 { int x; };
struct Type215 { int x; };
struct Type216 { int x; };
struct Type217 { int x; };
struct Type218 { int x; };
struct Type219 { int x; };
struct Type220 { int x; };
struct Type221 { int x; };
struct Type222 { int x; };
struct Type223 { int x; };
struct Type224 { int x; };
struct Type225 { int x; };
struct Type226 { int x; };
struct Type227 { int x; };
struct Type228 { int x; };
struct Type229 { int x; };
struct Type230 { int x; };
struct Type231 { int x; };
struct Type232 { int x; };
struct Type233 { int x; };
struct Type234 { int x; };
struct Type235 { int x; };
struct Type236 { int x; };
struct Type237 { int x; };
struct Type238 { int x; };
struct Type239 { int x; };
struct Type240 { int x; };
struct Type241 { int x; };
struct Type242 { int x; };
struct Type243 { int x; };
struct Type244 { int x; };
struct Type245 { int x; };
struct Type246 { int x; };
struct Type247 { int x; };
struct Type248 { int x; };
struct Type249 { int x; };
struct Type250 { int x; };
struct Type251 { int x; };
struct Type252 { int x; };
struct Type253 { int x; };
struct Type254 { int x; };
struct Type255 { int x; };

union.cpp

#include <stdio.h>
#include "types.h"

union MyVariant
{
    Type0   type0;
    Type1   type1;
    Type2   type2;
    Type3   type3;
    Type4   type4;
    Type5   type5;
    Type6   type6;
    Type7   type7;
    Type8   type8;
    Type9   type9;
    Type10  type10;
    Type11  type11;
    Type12  type12;
    Type13  type13;
    Type14  type14;
    Type15  type15;
    Type16  type16;
    Type17  type17;
    Type18  type18;
    Type19  type19;
    Type20  type20;
    Type21  type21;
    Type22  type22;
    Type23  type23;
    Type24  type24;
    Type25  type25;
    Type26  type26;
    Type27  type27;
    Type28  type28;
    Type29  type29;
    Type30  type30;
    Type31  type31;
    Type32  type32;
    Type33  type33;
    Type34  type34;
    Type35  type35;
    Type36  type36;
    Type37  type37;
    Type38  type38;
    Type39  type39;
    Type40  type40;
    Type41  type41;
    Type42  type42;
    Type43  type43;
    Type44  type44;
    Type45  type45;
    Type46  type46;
    Type47  type47;
    Type48  type48;
    Type49  type49;
    Type50  type50;
    Type51  type51;
    Type52  type52;
    Type53  type53;
    Type54  type54;
    Type55  type55;
    Type56  type56;
    Type57  type57;
    Type58  type58;
    Type59  type59;
    Type60  type60;
    Type61  type61;
    Type62  type62;
    Type63  type63;
    Type64  type64;
    Type65  type65;
    Type66  type66;
    Type67  type67;
    Type68  type68;
    Type69  type69;
    Type70  type70;
    Type71  type71;
    Type72  type72;
    Type73  type73;
    Type74  type74;
    Type75  type75;
    Type76  type76;
    Type77  type77;
    Type78  type78;
    Type79  type79;
    Type80  type80;
    Type81  type81;
    Type82  type82;
    Type83  type83;
    Type84  type84;
    Type85  type85;
    Type86  type86;
    Type87  type87;
    Type88  type88;
    Type89  type89;
    Type90  type90;
    Type91  type91;
    Type92  type92;
    Type93  type93;
    Type94  type94;
    Type95  type95;
    Type96  type96;
    Type97  type97;
    Type98  type98;
    Type99  type99;
    Type100 type100;
    Type101 type101;
    Type102 type102;
    Type103 type103;
    Type104 type104;
    Type105 type105;
    Type106 type106;
    Type107 type107;
    Type108 type108;
    Type109 type109;
    Type110 type110;
    Type111 type111;
    Type112 type112;
    Type113 type113;
    Type114 type114;
    Type115 type115;
    Type116 type116;
    Type117 type117;
    Type118 type118;
    Type119 type119;
    Type120 type120;
    Type121 type121;
    Type122 type122;
    Type123 type123;
    Type124 type124;
    Type125 type125;
    Type126 type126;
    Type127 type127;
    Type128 type128;
    Type129 type129;
    Type130 type130;
    Type131 type131;
    Type132 type132;
    Type133 type133;
    Type134 type134;
    Type135 type135;
    Type136 type136;
    Type137 type137;
    Type138 type138;
    Type139 type139;
    Type140 type140;
    Type141 type141;
    Type142 type142;
    Type143 type143;
    Type144 type144;
    Type145 type145;
    Type146 type146;
    Type147 type147;
    Type148 type148;
    Type149 type149;
    Type150 type150;
    Type151 type151;
    Type152 type152;
    Type153 type153;
    Type154 type154;
    Type155 type155;
    Type156 type156;
    Type157 type157;
    Type158 type158;
    Type159 type159;
    Type160 type160;
    Type161 type161;
    Type162 type162;
    Type163 type163;
    Type164 type164;
    Type165 type165;
    Type166 type166;
    Type167 type167;
    Type168 type168;
    Type169 type169;
    Type170 type170;
    Type171 type171;
    Type172 type172;
    Type173 type173;
    Type174 type174;
    Type175 type175;
    Type176 type176;
    Type177 type177;
    Type178 type178;
    Type179 type179;
    Type180 type180;
    Type181 type181;
    Type182 type182;
    Type183 type183;
    Type184 type184;
    Type185 type185;
    Type186 type186;
    Type187 type187;
    Type188 type188;
    Type189 type189;
    Type190 type190;
    Type191 type191;
    Type192 type192;
    Type193 type193;
    Type194 type194;
    Type195 type195;
    Type196 type196;
    Type197 type197;
    Type198 type198;
    Type199 type199;
    Type200 type200;
    Type201 type201;
    Type202 type202;
    Type203 type203;
    Type204 type204;
    Type205 type205;
    Type206 type206;
    Type207 type207;
    Type208 type208;
    Type209 type209;
    Type210 type210;
    Type211 type211;
    Type212 type212;
    Type213 type213;
    Type214 type214;
    Type215 type215;
    Type216 type216;
    Type217 type217;
    Type218 type218;
    Type219 type219;
    Type220 type220;
    Type221 type221;
    Type222 type222;
    Type223 type223;
    Type224 type224;
    Type225 type225;
    Type226 type226;
    Type227 type227;
    Type228 type228;
    Type229 type229;
    Type230 type230;
    Type231 type231;
    Type232 type232;
    Type233 type233;
    Type234 type234;
    Type235 type235;
    Type236 type236;
    Type237 type237;
    Type238 type238;
    Type239 type239;
    Type240 type240;
    Type241 type241;
    Type242 type242;
    Type243 type243;
    Type244 type244;
    Type245 type245;
    Type246 type246;
    Type247 type247;
    Type248 type248;
    Type249 type249;
    Type250 type250;
    Type251 type251;
    Type252 type252;
    Type253 type253;
    Type254 type254;
    Type255 type255;
};

int main()
{
    Type100 t;
    t.x = 10;
    MyVariant v;
    v.type100 = t;

    printf("%d\n", v.type100.x);
}

variant.cpp

#include <variant>
#include <stdio.h>
#include "types.h"

using MyVariant = std::variant<
    Type0,
    Type1,
    Type2,
    Type3,
    Type4,
    Type5,
    Type6,
    Type7,
    Type8,
    Type9,
    Type10,
    Type11,
    Type12,
    Type13,
    Type14,
    Type15,
    Type16,
    Type17,
    Type18,
    Type19,
    Type20,
    Type21,
    Type22,
    Type23,
    Type24,
    Type25,
    Type26,
    Type27,
    Type28,
    Type29,
    Type30,
    Type31,
    Type32,
    Type33,
    Type34,
    Type35,
    Type36,
    Type37,
    Type38,
    Type39,
    Type40,
    Type41,
    Type42,
    Type43,
    Type44,
    Type45,
    Type46,
    Type47,
    Type48,
    Type49,
    Type50,
    Type51,
    Type52,
    Type53,
    Type54,
    Type55,
    Type56,
    Type57,
    Type58,
    Type59,
    Type60,
    Type61,
    Type62,
    Type63,
    Type64,
    Type65,
    Type66,
    Type67,
    Type68,
    Type69,
    Type70,
    Type71,
    Type72,
    Type73,
    Type74,
    Type75,
    Type76,
    Type77,
    Type78,
    Type79,
    Type80,
    Type81,
    Type82,
    Type83,
    Type84,
    Type85,
    Type86,
    Type87,
    Type88,
    Type89,
    Type90,
    Type91,
    Type92,
    Type93,
    Type94,
    Type95,
    Type96,
    Type97,
    Type98,
    Type99,
    Type100,
    Type101,
    Type102,
    Type103,
    Type104,
    Type105,
    Type106,
    Type107,
    Type108,
    Type109,
    Type110,
    Type111,
    Type112,
    Type113,
    Type114,
    Type115,
    Type116,
    Type117,
    Type118,
    Type119,
    Type120,
    Type121,
    Type122,
    Type123,
    Type124,
    Type125,
    Type126,
    Type127,
    Type128,
    Type129,
    Type130,
    Type131,
    Type132,
    Type133,
    Type134,
    Type135,
    Type136,
    Type137,
    Type138,
    Type139,
    Type140,
    Type141,
    Type142,
    Type143,
    Type144,
    Type145,
    Type146,
    Type147,
    Type148,
    Type149,
    Type150,
    Type151,
    Type152,
    Type153,
    Type154,
    Type155,
    Type156,
    Type157,
    Type158,
    Type159,
    Type160,
    Type161,
    Type162,
    Type163,
    Type164,
    Type165,
    Type166,
    Type167,
    Type168,
    Type169,
    Type170,
    Type171,
    Type172,
    Type173,
    Type174,
    Type175,
    Type176,
    Type177,
    Type178,
    Type179,
    Type180,
    Type181,
    Type182,
    Type183,
    Type184,
    Type185,
    Type186,
    Type187,
    Type188,
    Type189,
    Type190,
    Type191,
    Type192,
    Type193,
    Type194,
    Type195,
    Type196,
    Type197,
    Type198,
    Type199,
    Type200,
    Type201,
    Type202,
    Type203,
    Type204,
    Type205,
    Type206,
    Type207,
    Type208,
    Type209,
    Type210,
    Type211,
    Type212,
    Type213,
    Type214,
    Type215,
    Type216,
    Type217,
    Type218,
    Type219,
    Type220,
    Type221,
    Type222,
    Type223,
    Type224,
    Type225,
    Type226,
    Type227,
    Type228,
    Type229,
    Type230,
    Type231,
    Type232,
    Type233,
    Type234,
    Type235,
    Type236,
    Type237,
    Type238,
    Type239,
    Type240,
    Type241,
    Type242,
    Type243,
    Type244,
    Type245,
    Type246,
    Type247,
    Type248,
    Type249,
    Type250,
    Type251,
    Type252,
    Type253,
    Type254,
    Type255>;

int main()
{
    Type100 t;
    t.x = 10;
    MyVariant v;
    v = t;

    printf("%d\n", std::get<Type100>(v).x);
}