diff --git a/base.cpp b/base.cpp
index 94740c5..2353739 100644
--- a/base.cpp
+++ b/base.cpp
@@ -68,7 +68,9 @@
 
 #if OS_WINDOWS
     #define NOMINMAX
-    #define _CRT_SECURE_NO_WARNINGS
+    #ifndef _CRT_SECURE_NO_WARNINGS
+        #define _CRT_SECURE_NO_WARNINGS
+    #endif
     #include <windows.h>
     #define Breakpoint __debugbreak()
     #define force_inline __forceinline
diff --git a/base_arena.cpp b/base_arena.cpp
index 83cb045..cadd04d 100644
--- a/base_arena.cpp
+++ b/base_arena.cpp
@@ -131,7 +131,7 @@ arena_from_buffer(void *buffer, size_t size) {
 
 struct Scoped_Arena {
     Arena *arena;
-    int pos;
+    size_t pos;
     Scoped_Arena(Arena *arena) {
         this->arena = arena;
         this->pos = arena->len;
diff --git a/base_data_structures.cpp b/base_data_structures.cpp
index e9c3430..9780344 100644
--- a/base_data_structures.cpp
+++ b/base_data_structures.cpp
@@ -1,146 +1,8 @@
-
-//-----------------------------------------------------------------------------
-// Array
-//-----------------------------------------------------------------------------
-template <class T>
-struct Array {
-    Allocator *allocator;
-    T *data;
-    S64 cap;
-    S64 len;
-
-    T *push_empty(S64 count = 1) {
-        grow(count);
-        T *result = data + len;
-        len += count;
-        return result;
-    }
-
-    T *push_empty_zero(S64 count = 1) {
-        T *result = push_empty(count);
-        memory_zero(result, count * sizeof(T));
-        return result;
-    }
-
-    void grow(S64 required_size) {
-        if (cap == 0) {
-            S64 new_cap = max(required_size * 2, (S64)16);
-            data = allocate_array(allocator, T, new_cap);
-            cap = new_cap;
-        }
-        else if (len + required_size > cap) {
-            U64 new_cap = max(cap * 2, len + required_size + 1);
-            T *new_data = allocate_array(allocator, T, new_cap);
-            memory_copy(new_data, data, cap * sizeof(T));
-            deallocate(allocator, data);
-            data = new_data;
-            cap = new_cap;
-        }
-    }
-
-    void dealloc() {
-        if (data) deallocate(allocator, data);
-    }
-
-    S64 get_index(T *item) {
-        assert((data <= item) && ((data + len) > item));
-        size_t offset = item - data;
-        return (S64)offset;
-    }
-
-    void add(Array<T> items) {
-        For(items) {
-            add(it);
-        }
-    }
-
-#if 0
-    void insert(T item, int index) {
-        if (index == len) {
-            add(item);
-            return;
-        }
-
-        assert(index < len);
-        assert(index >= 0);
-
-        grow(1);
-        int right_len = len - index;
-        memmove(data + index + 1, data + index, sizeof(T) * right_len);
-        data[index] = item;
-        len += 1;
-    }
-#endif
-
-    void add(T item) {
-        grow(1);
-        data[len++] = item;
-    }
-
-    S64 addi(T item) {
-        S64 result = len;
-        grow(1);
-        data[len++] = item;
-        return result;
-    }
-
-    void unordered_remove(T *item) {
-        assert(len > 0);
-        assert((data <= item) && ((data + len) > item));
-        *item = data[--len];
-    }
-
-    void init(Allocator *a, S64 size = 16) {
-        allocator = a;
-        data = allocate_array(a, T, size);
-        cap = size;
-        len = 0;
-    }
-
-    Array<T> copy(Allocator *a) {
-        Array<T> result = {};
-        result.len = len;
-        result.cap = len * 2;
-        result.allocator = a;
-        result.data = allocate_array(a, T, result.cap);
-        memory_copy(result.data, data, sizeof(T) * result.len);
-        return result;
-    }
-
-    Array<T> tight_copy(Allocator *a) {
-        Array<T> result = {};
-        result.len = len;
-        result.cap = len;
-        result.allocator = 0;
-        result.data = allocate_array(a, T, len);
-        memory_copy(result.data, data, sizeof(T) * len);
-        return result;
-    }
-
-    void ordered_remove(T &item) { // Dont use in loops !!!!
-        assert(len > 0);
-        assert(&item >= begin() && &item < end());
-        int index = get_index(&item);
-        assert(index >= 0 && index < len);
-
-        int right_len = len - index - 1;
-        memmove(data + index, data + index + 1, right_len * sizeof(T));
-        len -= 1;
-    }
-
-    force_inline B32 is_last(T *item) { return item == last(); }
-    force_inline B32 is_first(T *item) { return item == begin(); }
-    force_inline void clear() { len = 0; }
-    force_inline void reset() { len = 0; }
-    force_inline T pop() { return data[--len]; }
-    force_inline T *last() { return data + len - 1; }
-    force_inline T *begin() { return data; }
-    force_inline T *end() { return data + len; }
-    force_inline T &operator[](S64 i) {
-        assert(i >= 0 && i < cap);
-        return data[i];
-    }
-};
+#define ARRAY_ALLOCATOR_TYPE Allocator
+#define ARRAY_ASSERT assert
+#define ARRAY_ALLOCATE(allocator, size) allocate_size(allocator, size)
+#define ARRAY_DEALLOCATE(allocator, p) deallocate(allocator, p)
+#include "core/array.hpp"
 
 //-----------------------------------------------------------------------------
 // Map
diff --git a/build.bat b/build.bat
index a4fb019..52cd11d 100644
--- a/build.bat
+++ b/build.bat
@@ -1,20 +1,9 @@
 @echo off
-if exist "..\misc\compile_setup.bat" call "..\misc\compile_setup.bat"
+bld --dont_compile_core
+rem if exist "..\misc\compile_setup.bat" call "..\misc\compile_setup.bat"
 
-set clang-flags=-O0 -Wall -Wno-unused-function -fno-exceptions -fdiagnostics-absolute-paths -g -o main.exe -Wl,user32.lib
+rem set clang-flags=-O0 -Wall -Wno-unused-function -fno-exceptions -fdiagnostics-absolute-paths -g -o main.exe -Wl,user32.lib
 
-pushd %~dp0
-cl core_main.cpp -Zi -nologo -W3 -wd4200 -wd4267 -wd4244 -diagnostics:column -Fe:main.exe user32.lib
-rem clang core_main.cpp %clang-flags%
-rem ubuntu run clang core_main.cpp -O0 -Wall -Wno-unused-function -fno-exceptions -fdiagnostics-absolute-paths -g -o core.out
-
-rem clang core_arena.cpp %clang-flags%
-
-rem clang test.cpp
-
-rem main.exe -testing
-rem echo Building arms race
-rem call examples/arms_race/build_arms_race.bat
-rem main examples/arms_race/arms_race.core
-
-popd
+rem pushd %~dp0
+rem cl core_main.cpp -Zi -nologo -W3 -wd4200 -wd4267 -wd4244 -diagnostics:column -Fe:main.exe user32.lib
+rem popd
diff --git a/c3_big_int.cpp b/c3_big_int.cpp
index f4c0700..9ffe10e 100644
--- a/c3_big_int.cpp
+++ b/c3_big_int.cpp
@@ -1437,7 +1437,7 @@ void bigint_shl_int(BigInt *dest, const BigInt *op1, uint64_t shift) {
     uint64_t leftover_shift_count = shift % 64;
 
     dest->digits = ALLOC_DIGITS(op1->digit_count + digit_shift_count + 1);
-    dest->digit_count = digit_shift_count;
+    dest->digit_count = (unsigned)digit_shift_count;
     uint64_t carry = 0;
     for (size_t i = 0; i < op1->digit_count; i += 1) {
         uint64_t digit = op1_digits[i];
@@ -1495,7 +1495,7 @@ void bigint_shr(BigInt *dest, const BigInt *op1, const BigInt *op2) {
         return bigint_init_unsigned(dest, 0);
     }
 
-    dest->digit_count = op1->digit_count - digit_shift_count;
+    dest->digit_count = (unsigned)(op1->digit_count - digit_shift_count);
     uint64_t *digits;
     if (dest->digit_count == 1) {
         digits = &dest->digit;
diff --git a/core_codegen_c_language.cpp b/core_codegen_c_language.cpp
index b7d399b..a8bafba 100644
--- a/core_codegen_c_language.cpp
+++ b/core_codegen_c_language.cpp
@@ -477,7 +477,7 @@ gen_expr(Ast_Expr *ast) {
             gen("%Q(", node->resolved_decl->unique_name);
             For(node->exprs) {
                 gen_try_any_or_slice(it->item, it->resolved_type);
-                if (!node->exprs.is_last(&it)) gen(", ");
+                if (!node->exprs.is_last(it)) gen(", ");
             }
             gen(")");
             BREAK();
@@ -507,7 +507,7 @@ gen_expr(Ast_Expr *ast) {
                     gen("[%d] = ", (int)it->resolved_index);
                 gen_try_any_or_slice(it->item, it->resolved_type);
 
-                if (!node->exprs.is_last(&it)) gen(", ");
+                if (!node->exprs.is_last(it)) gen(", ");
             }
 
             if (is_slice(node->resolved_type)) gen("}");
@@ -612,7 +612,7 @@ gen_ast(Ast *ast) {
                     gen(";");
                     genln("");
                 }
-                if (node->ifs.is_first(&it)) {
+                if (node->ifs.is_first(it)) {
                     gen("if(");
                     gen_expr(it->expr);
                     gen(")");
@@ -971,7 +971,7 @@ compile_to_c_code() {
             For(type->agg.members) {
                 genln("");
                 // @todo remove intern from gen
-                Intern_String name = pctx->internf("m%llu", type->agg.members.get_index(&it));
+                Intern_String name = pctx->internf("m%llu", type->agg.members.get_index(it));
                 gen_simple_decl(it.type, name);
                 gen(";");
             }
diff --git a/core_lexing.cpp b/core_lexing.cpp
index a37efb1..4373646 100644
--- a/core_lexing.cpp
+++ b/core_lexing.cpp
@@ -196,7 +196,7 @@ token_make(Core_Ctx *lexer) {
 CORE_Static Token *
 lex_last_indent_token(Lex_Stream *s) {
     if (s->indent_stack.len > 0) {
-        return *s->indent_stack.last();
+        return *s->indent_stack.back();
     }
     return &pctx->same_scope_token;
 }
@@ -326,7 +326,7 @@ lex__stream(Core_Ctx *lexer) {
                         semi.kind = OPEN_SCOPE;
                         semi.indent = last->indent + 2; // @todo: proper detection of indentation
                         lex_add_token(lexer, &semi);
-                        s->indent_stack.add(lexer->tokens.last());
+                        s->indent_stack.add(lexer->tokens.back());
                     }
                     else {
                         semi.kind = SAME_SCOPE;
@@ -347,7 +347,7 @@ lex__stream(Core_Ctx *lexer) {
                         if (t.indent > last->indent) {
                             t.kind = OPEN_SCOPE;
                             lex_add_token(lexer, &t);
-                            s->indent_stack.add(lexer->tokens.last());
+                            s->indent_stack.add(lexer->tokens.back());
                         }
 
                         else if (t.indent < last->indent) {
diff --git a/core_polymorph.cpp b/core_polymorph.cpp
index 002ad82..b07804f 100644
--- a/core_polymorph.cpp
+++ b/core_polymorph.cpp
@@ -58,7 +58,7 @@ Ast *ast_copy(Ast *ast, Ast_Scope *parent_scope, Array<Ast_Decl *> *replace, Arr
                 For(*replace) {
                     assert(it->type == pctx->type_type);
                     if (it->name == dst->intern_val) {
-                        int it_index = replace->get_index(&it);
+                        S64 it_index = replace->get_index(it);
                         Ast_Call_Item *replacement = with[0][it_index];
                         Ast *replacement_v = replacement->item;
                         dst = (Ast_Atom *)ast_copy(replacement_v, parent_scope, 0, 0);
diff --git a/core_printer.cpp b/core_printer.cpp
index 91f6694..f5fe979 100644
--- a/core_printer.cpp
+++ b/core_printer.cpp
@@ -35,7 +35,7 @@ core_type_to_string(Ast_Type *type) {
             For(args) {
                 String t = core_type_to_string(it);
                 b->addf("%Q", t);
-                if (!args.is_last(&it)) b->addf(", ");
+                if (!args.is_last(it)) b->addf(", ");
             }
             b->addf(")");
             if (type->func.ret) {
@@ -160,7 +160,7 @@ void core__stringify(Ast *ast) {
             gen("(");
             For(n->exprs) {
                 core__stringify(it);
-                if (!n->exprs.is_last(&it)) gen(",");
+                if (!n->exprs.is_last(it)) gen(",");
             }
             gen(")");
         } break;
@@ -228,7 +228,7 @@ void core__stringify(Ast *ast) {
             Ast_Var_Unpack *n = (Ast_Var_Unpack *)ast;
             For(n->vars) {
                 core__stringify(it);
-                if (!n->vars.is_last(&it)) gen(",");
+                if (!n->vars.is_last(it)) gen(",");
             }
             gen(" = ");
             core__stringify(n->expr);
@@ -328,7 +328,7 @@ void core__stringify(Ast *ast) {
             gen("return ");
             For(n->expr) {
                 core__stringify(it);
-                if (!n->expr.is_last(&it)) gen(", ");
+                if (!n->expr.is_last(it)) gen(", ");
             }
         } break;
 
@@ -338,14 +338,14 @@ void core__stringify(Ast *ast) {
             gen("(");
             For(n->args) {
                 core__stringify(it);
-                if (!n->args.is_last(&it)) gen(", ");
+                if (!n->args.is_last(it)) gen(", ");
             }
             gen(")");
 
             if (n->ret.len) gen(": ");
             For(n->ret) {
                 core__stringify(it);
-                if (!n->ret.is_last(&it)) gen(", ");
+                if (!n->ret.is_last(it)) gen(", ");
             }
 
             core__stringify(n->scope);
diff --git a/core_typechecking.cpp b/core_typechecking.cpp
index 05614e4..ebb1a62 100644
--- a/core_typechecking.cpp
+++ b/core_typechecking.cpp
@@ -884,7 +884,7 @@ resolve_stmt(Ast *ast, Ast_Type *ret) {
                 node->resolved_type = expr_op.type;
 
                 For(node->vars) {
-                    S64 index = node->vars.get_index(&it);
+                    S64 index = node->vars.get_index(it);
                     Ast_Resolved_Member *type = expr_op.type->agg.members.data + index;
                     it->type = type->type;
                     resolve_decl(it);
@@ -1044,7 +1044,7 @@ resolve_compound_array(Ast_Call *node, Ast_Type *type) {
         else {
             if (default_counter == -1)
                 compiler_error(it->pos, "Mixing expicit indexes and default is illegal");
-            it->resolved_index = default_counter;
+            it->resolved_index = (S32)default_counter;
         }
 
         Operand item = resolve_expr(it->item, AST_CANT_BE_NULL, item_type, 0);
@@ -1069,7 +1069,7 @@ resolve_compound_struct(Ast_Call *node, Ast_Type *type) {
             For_Named(type->agg.members, m) {
                 if (it->name->intern_val == m.name) {
                     it->resolved_name = m.name;
-                    it->resolved_index = type->agg.members.get_index(&m);
+                    it->resolved_index = (S32)type->agg.members.get_index(m);
                     // @copy_paste
                     if (m.type == pctx->type_type)
                         item_type = m.type_val;
@@ -1095,7 +1095,7 @@ resolve_compound_struct(Ast_Call *node, Ast_Type *type) {
 
             Ast_Resolved_Member *m = &type->agg.members[default_counter];
             it->resolved_name = m->name;
-            it->resolved_index = default_counter;
+            it->resolved_index = (S32)default_counter;
             m->visited = true;
 
             // @copy_paste
@@ -1187,7 +1187,7 @@ resolve_expr(Ast_Expr *ast, Resolve_Flag flags, Ast_Type *compound_and_const_str
 
             if (node->expr) {
                 type_complete(type.type_val);
-                type.type_val = type_array(type.type_val, bigint_as_unsigned(&expr.big_int_val));
+                type.type_val = type_array(type.type_val, (S32)bigint_as_unsigned(&expr.big_int_val));
             }
             else {
                 type.type_val = type_slice(type.type_val, node);
@@ -1651,7 +1651,7 @@ resolve_expr(Ast_Expr *ast, Resolve_Flag flags, Ast_Type *compound_and_const_str
 
                     Ast_Call_Item *item = 0;
                     For(node->exprs) {
-                        int it_index = node->exprs.get_index(&it);
+                        S64 it_index = node->exprs.get_index(it);
 
                         bool named_argument = is_flag_set(it->call_flags, CALL_NAME);
                         bool named_argument_already_appeared = it_index > default_iter;
diff --git a/core_types.cpp b/core_types.cpp
index 0b66ad4..0b5bab9 100644
--- a/core_types.cpp
+++ b/core_types.cpp
@@ -59,7 +59,7 @@ force_inline B32 is_numeric(Ast_Type *type) {
 // Hash consed types
 //-----------------------------------------------------------------------------
 CORE_Static Ast_Type *
-type_new(Allocator *allocator, Ast_Type_Kind kind, size_t size, size_t align) {
+type_new(Allocator *allocator, Ast_Type_Kind kind, int32_t size, int32_t align) {
     Ast_Type *result = allocate_struct(allocator, Ast_Type, true);
     result->kind = kind;
     result->size = size;
@@ -147,7 +147,7 @@ type_try_tupling(Array<Ast_Type *> types, Ast *ast) {
 }
 
 CORE_Static Ast_Type *
-type_array(Ast_Type *base, S64 size) {
+type_array(Ast_Type *base, S32 size) {
     U64 hash_base = hash_ptr(base);
     U64 hash = hash_mix(hash_base, hash_u64(size));
     Ast_Type *result = (Ast_Type *)map_get(&pctx->type_map, hash);
@@ -237,7 +237,7 @@ type_struct_complete(Ast_Type *type, Ast_Decl *node) {
         //
         Array<Ast_Resolved_Member> members = {scratch.arena};
         type->kind = TYPE_COMPLETING;
-        size_t members_size = 0;
+        S32 members_size = 0;
         For(node->scope->decls) {
             resolve_decl(it);
             assert(it->type->kind != TYPE_INCOMPLETE);
@@ -247,7 +247,7 @@ type_struct_complete(Ast_Type *type, Ast_Decl *node) {
             m.offset = type->size;
             members_size += it->type->size;
             type->align = max(type->align, it->type->align);
-            type->size = it->type->size + align_up(type->size, it->type->align);
+            type->size = it->type->size + (S32)align_up(type->size, it->type->align);
 
             m.name = it->name;
             m.value = it->value;
@@ -257,7 +257,7 @@ type_struct_complete(Ast_Type *type, Ast_Decl *node) {
         //
         // Then compute size of struct itself
         //
-        type->size = align_up(type->size, type->align);
+        type->size = (S32)align_up(type->size, type->align);
         type->padding = type->size - members_size;
         type->agg.members = members.tight_copy(pctx->perm);
         type->kind = TYPE_STRUCT;
@@ -285,7 +285,7 @@ type_struct_complete(Ast_Type *type, Ast_Decl *node) {
         //
         // Then compute size of union itself
         //
-        type->size = align_up(type->size, type->align);
+        type->size = (S32)align_up(type->size, type->align);
         type->agg.members = members.tight_copy(pctx->perm);
         type->kind = TYPE_UNION;
     }
@@ -321,7 +321,7 @@ typename_base(String_Builder *sb, Ast_Type *type) {
             sb->addf("(");
             For(type->func.args) {
                 typename_base(sb, it);
-                if (!type->func.args.is_last(&it)) sb->addf(", ");
+                if (!type->func.args.is_last(it)) sb->addf(", ");
             }
 
             sb->addf("):");
diff --git a/stb_sprintf.h b/stb_sprintf.h
index 160c28a..4ddc601 100644
--- a/stb_sprintf.h
+++ b/stb_sprintf.h
@@ -593,7 +593,7 @@ STBSP__PUBLICDEF int STB_SPRINTF_DECORATE(vsprintfcb)(STBSP_SPRINTFCB *callback,
                 str = va_arg(va, String);
                 if (str.str == 0 && str.len != 0)
                     str = string_null;
-                pr = str.len;
+                pr = (int)str.len;
                 s = (char *)str.str;
                 l = stbsp__strlen_limited(s, (pr >= 0) ? pr : ~0u);
                 lead[0] = 0;