调用 std::max 时出现问题

问题描述

我在 Visual Studio 中编译了我的野牛生成的文件，并得到了这些错误:

I compiled my bison-generated files in Visual Studio and got these errors:

...position.hh(83): error C2589: '(' : '::'右侧的非法标记
...position.hh(83):错误 C2059:语法错误:'::'
...position.hh(83): error C2589: '(' : '::'右侧的非法标记
...position.hh(83):错误 C2059:语法错误:'::'

...position.hh(83): error C2589: '(' : illegal token on right side of '::'
...position.hh(83): error C2059: syntax error : '::'
...position.hh(83): error C2589: '(' : illegal token on right side of '::'
...position.hh(83): error C2059: syntax error : '::'

对应的代码为:

inline void columns (int count = 1)
{
  column = std::max (1u, column + count);
}

我认为问题在于 std::max;如果我将 std::max 更改为等效代码，那么就没有问题了，但是有没有更好的解决方案而不是更改生成的代码?

I think the problem is with std::max; if I change std::max to equivalent code then there is no problem anymore, but is there a better solution instead of changing the generated code?

这是我写的野牛文件:

//
// bison.yy
//

%skeleton "lalr1.cc"
%require "2.4.2"
%defines
%define parser_class_name "cmd_parser"
%locations
%debug
%error-verbose

%code requires {
class ParserDriver;
}

%parse-param { ParserDriver& driver }
%lex-param { ParserDriver& driver }

%union {
    struct ast *a;
    double d;
    struct symbol *s;   
    struct symlist *sl;
    int fn;         
}

%code {
#include "helper_func.h"
#include "ParserDriver.h"
std::string error_msg = "";
}

%token <d> NUMBER
%token <s> NAME
%token <fn> FUNC
%token EOL
%token IF THEN ELSE WHILE DO LET
%token SYM_TABLE_OVERFLOW
%token UNKNOWN_CHARACTER

%nonassoc <fn> CMP
%right '='
%left '+' '-'
%left '*' '/'
%nonassoc '|' UMINUS

%type <a> exp stmt list explist
%type <sl> symlist

%{
extern int yylex(yy::cmd_parser::semantic_type *yylval,
 yy::cmd_parser::location_type* yylloc);
%}

%start calclist
%%

... grammar rules ...

推荐答案

你可能在某处包含了 windows.h，它定义了名为 max 和 min 的宏.

You are probably including windows.h somewhere, which defines macros named max and min.

您可以在包含 windows.h 之前#define NOMINMAX 以防止它定义这些宏，或者您可以使用一组额外的括号来防止宏调用:

You can #define NOMINMAX before including windows.h to prevent it from defining those macros, or you can prevent macro invocation by using an extra set of parentheses:

column = (std::max)(1u, column + count);

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