Strange compiler error in MSVC10 - c++

Question

I've got the following code:
std::for_each(tokens.begin(), tokens.end(), [&](Token& t) {
static const std::unordered_map<std::wstring, Wide::Lexer::TokenType> mapping([]() -> std::unordered_map<std::wstring, Wide::Lexer::TokenType>
{
// Maps strings to TokenType enumerated values
std::unordered_map<std::wstring, Wide::Lexer::TokenType> result;
// RESERVED WORD
result[L"namespace"] = Wide::Lexer::TokenType::Namespace;
result[L"for"] = Wide::Lexer::TokenType::For;
result[L"while"] = Wide::Lexer::TokenType::While;
result[L"do"] = Wide::Lexer::TokenType::Do;
result[L"type"] = Wide::Lexer::TokenType::Type;
// PUNCTUATION
result[L"{"] = Wide::Lexer::TokenType::OpenCurlyBracket;
result[L"}"] = Wide::Lexer::TokenType::CloseCurlyBacket;
return result;
}());
if (mapping.find(t.Codepoints) != mapping.end()) {
t.type = mapping.find(t.Codepoints)->second;
return;
}
t.type = Wide::Lexer::TokenType::Identifier; // line 121
});
This iterates through a list of tokens, and judging by the contents of the codepoints, assigns them a value from the associated enum. If it's not found, then give it a value of "Identifier". But this fails to compile.
1>Lexer.cpp(121): error C2065: '__this' : undeclared identifier
1>Lexer.cpp(121): error C2227: left of '->Identifier' must point to class/struct/union/generic type
This is the full error, no warnings, no other errors. What? How can I fix this error?
Edit: I did some significant refactoring, and I've got the exact same problem in a somewhat simpler lambda.
auto end_current_token = [&] {
if (current != Wide::Lexer::Token()) {
current.type = Wide::Lexer::TokenType::Identifier; // error line
if (reserved_words.find(current.Codepoints) != reserved_words.end())
current.type = reserved_words.find(current.Codepoints)->second;
if (punctuation.find(current.Codepoints[0]) != punctuation.end())
current.type = punctuation.find(current.Codepoints[0])->second;
tokens.push_back(current);
current = Wide::Lexer::Token();
}
};
I've cleaned and rebuilt the project.
I fixed the problem.
auto end_current_token = [&] {
if (current != Wide::Lexer::Token()) {
// WORKAROUND compiler bug- dead code
struct bug_workaround_type {
int Identifier;
};
bug_workaround_type bug;
bug_workaround_type* __this = &bug;
current.type = Wide::Lexer::TokenType::Identifier;
if (reserved_words.find(current.Codepoints) != reserved_words.end())
current.type = reserved_words.find(current.Codepoints)->second;
if (punctuation.find(current.Codepoints[0]) != punctuation.end())
current.type = punctuation.find(current.Codepoints[0])->second;
tokens.push_back(current);
current = Wide::Lexer::Token();
}
};
No, really. Now it compiles and runs just fine.

Answer 1

FWIW I tried to concoct a minimal working sample in order to compile on VS2010 and compiled the following without error.
#include <string>
#include <vector>
#include <algorithm>
#include <unordered_map>
namespace Wide { namespace Lexer {
enum TokenType
{
OpenCurlyBracket,
CloseCurlyBacket,
Namespace,
For,
While,
Do,
Type,
Identifier,
};
} }
struct Token
{
std::wstring Codepoints;
Wide::Lexer::TokenType type;
};
int main()
{
std::vector<Token> tokens;
std::for_each(tokens.begin(), tokens.end(), [&](Token& t) {
static const std::unordered_map<std::wstring, Wide::Lexer::TokenType> mapping([]() -> std::unordered_map<std::wstring, Wide::Lexer::TokenType>
{
// Maps strings to TokenType enumerated values
std::unordered_map<std::wstring, Wide::Lexer::TokenType> result;
// RESERVED WORD
result[L"namespace"] = Wide::Lexer::TokenType::Namespace;
result[L"for"] = Wide::Lexer::TokenType::For;
result[L"while"] = Wide::Lexer::TokenType::While;
result[L"do"] = Wide::Lexer::TokenType::Do;
result[L"type"] = Wide::Lexer::TokenType::Type;
// PUNCTUATION
result[L"{"] = Wide::Lexer::TokenType::OpenCurlyBracket;
result[L"}"] = Wide::Lexer::TokenType::CloseCurlyBacket;
return result;
}());
if (mapping.find(t.Codepoints) != mapping.end()) {
t.type = mapping.find(t.Codepoints)->second;
return;
}
t.type = Wide::Lexer::TokenType::Identifier; // line 121
});
}
Could you bisect the minimum edit that show the problem, starting from this code?

Answer 2

I've got the same problem right now. I used other types, but for your case it will be like this:
auto end_current_token = [&] {
using Wide::Lexer::TokenType; // <-- this line solves problem
if (current != Wide::Lexer::Token()) {
current.type = Wide::Lexer::TokenType::Identifier;
Now it compiles well.